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Matsui T, Rajkovic I, Mooers BHM, Liu P, Weiss TM. Adaptable SEC-SAXS data collection for higher quality structure analysis in solution. Protein Sci 2024; 33:e4946. [PMID: 38501481 PMCID: PMC10949327 DOI: 10.1002/pro.4946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 01/31/2024] [Accepted: 02/10/2024] [Indexed: 03/20/2024]
Abstract
The two major challenges in synchrotron size-exclusion chromatography coupled in-line with small-angle x-ray scattering (SEC-SAXS) experiments are the overlapping peaks in the elution profile and the fouling of radiation-damaged materials on the walls of the sample cell. In recent years, many post-experimental analyses techniques have been developed and applied to extract scattering profiles from these problematic SEC-SAXS data. Here, we present three modes of data collection at the BioSAXS Beamline 4-2 of the Stanford Synchrotron Radiation Lightsource (SSRL BL4-2). The first mode, the High-Resolution mode, enables SEC-SAXS data collection with excellent sample separation and virtually no additional peak broadening from the UHPLC UV detector to the x-ray position by taking advantage of the low system dispersion of the UHPLC. The small bed volume of the analytical SEC column minimizes sample dilution in the column and facilitates data collection at higher sample concentrations with excellent sample economy equal to or even less than that of the conventional equilibrium SAXS method. Radiation damage problems during SEC-SAXS data collection are evaded by additional cleaning of the sample cell after buffer data collection and avoidance of unnecessary exposures through the use of the x-ray shutter control options, allowing sample data collection with a clean sample cell. Therefore, accurate background subtraction can be performed at a level equivalent to the conventional equilibrium SAXS method without requiring baseline correction, thereby leading to more reliable downstream structural analysis and quicker access to new science. The two other data collection modes, the High-Throughput mode and the Co-Flow mode, add agility to the planning and execution of experiments to efficiently achieve the user's scientific objectives at the SSRL BL4-2.
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Affiliation(s)
- Tsutomu Matsui
- Stanford Synchrotron Radiation LightsourceSLAC National Accelerator LaboratoryMenlo ParkCaliforniaUSA
| | - Ivan Rajkovic
- Stanford Synchrotron Radiation LightsourceSLAC National Accelerator LaboratoryMenlo ParkCaliforniaUSA
| | - Blaine H. M. Mooers
- Department of Biochemistry and PhysiologyUniversity of Oklahoma Health Sciences CenterOklahoma CityOklahomaUSA
- Stephenson Cancer CenterUniversity of Oklahoma Health Sciences CenterOklahoma CityOklahomaUSA
- Laboratory of Biomolecular Structure and FunctionUniversity of Oklahoma Health Sciences CenterOklahoma CityOklahomaUSA
| | - Ping Liu
- Stanford Synchrotron Radiation LightsourceSLAC National Accelerator LaboratoryMenlo ParkCaliforniaUSA
| | - Thomas M. Weiss
- Stanford Synchrotron Radiation LightsourceSLAC National Accelerator LaboratoryMenlo ParkCaliforniaUSA
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2
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Behera J, Rahman MM, Shockey J, Kilaru A. Acyl-CoA-dependent and acyl-CoA-independent avocado acyltransferases positively influence oleic acid content in nonseed triacylglycerols. FRONTIERS IN PLANT SCIENCE 2023; 13:1056582. [PMID: 36714784 PMCID: PMC9874167 DOI: 10.3389/fpls.2022.1056582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 12/15/2022] [Indexed: 06/18/2023]
Abstract
In higher plants, acyl-CoA:diacylglycerol acyltransferase (DGAT) and phospholipid:diacylglycerol acyltransferase (PDAT) catalyze the terminal step of triacylglycerol (TAG) synthesis in acyl-CoA-dependent and -independent pathways, respectively. Avocado (Persea americana) mesocarp, a nonseed tissue, accumulates significant amounts of TAG (~70% by dry weight) that is rich in heart-healthy oleic acid (18:1). The oil accumulation stages of avocado mesocarp development coincide with high expression levels for type-1 DGAT (DGAT1) and PDAT1, although type-2 DGAT (DGAT2) expression remains low. The strong preference for oleic acid demonstrated by the avocado mesocarp TAG biosynthetic machinery represents lucrative biotechnological opportunities, yet functional characterization of these three acyltransferases has not been explored to date. We expressed avocado PaDGAT1, PaDGAT2, and PaPDAT1 in bakers' yeast and leaves of Nicotiana benthamiana. PaDGAT1 complemented the TAG biosynthesis deficiency in the quadruple mutant yeast strain H1246, and substantially elevated total cellular lipid content. In vitro enzyme assays showed that PaDGAT1 prefers oleic acid compared to palmitic acid (16:0). Both PaDGAT1 and PaPDAT1 increased the lipid content and elevated oleic acid levels when expressed independently or together, transiently in N. benthamiana leaves. These results indicate that PaDGAT1 and PaPDAT1 prefer oleate-containing substrates, and their coordinated expression likely contributes to sustained TAG synthesis that is enriched in oleic acid. This study establishes a knowledge base for future metabolic engineering studies focused on exploitation of the biochemical properties of PaDGAT1 and PaPDAT1.
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Affiliation(s)
- Jyoti Behera
- Department of Biological Sciences, East Tennessee State University, Johnson City, TN, United States
| | - Md Mahbubur Rahman
- Department of Biological Sciences, East Tennessee State University, Johnson City, TN, United States
- dNTP Laboratory, Teaneck, NJ, United States
| | - Jay Shockey
- U.S. Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, Commodity Utilization Research Unit, New Orleans, LA, United States
| | - Aruna Kilaru
- Department of Biological Sciences, East Tennessee State University, Johnson City, TN, United States
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3
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Panigrahi R, Kailasam S. Mapping allosteric pathway in NIa-Pro using computational approach. QUANTITATIVE BIOLOGY 2023. [DOI: 10.15302/j-qb-022-0296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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4
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Panigrahi R, Glover JNM, Nallusamy S. A look into DGAT1 through the EM lenses. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2023; 1865:184069. [PMID: 36216097 DOI: 10.1016/j.bbamem.2022.184069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 10/03/2022] [Indexed: 11/05/2022]
Abstract
With the advent of modern detectors and robust structure solution pipeline, cryogenic electron microscopy has recently proved to be game changer in structural biology. Membrane proteins are challenging targets for structural biologists. This minireview focuses a membrane embedded triglyceride synthesizing machine, DGAT1. Decades of research had built the foundational knowledge on this enzyme's activity. However, recently solved cryo-EM structures of this enzyme, in apo and bound form, has provided critical mechanistic insights. The flipping of the catalytic histidine is critical of enzyme catalysis. The structures explain why the enzyme has preference to long fatty acyl chains over the short forms.
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Affiliation(s)
- Rashmi Panigrahi
- Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada.
| | - J N Mark Glover
- Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Saranya Nallusamy
- Department of Plant Molecular Biology and Bioinformatics, Centre for Plant Molecular Biology and Biotechnology, Tamil Nadu Agricultural University, Coimbatore 641003, India.
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5
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Chen G, Harwood JL, Lemieux MJ, Stone SJ, Weselake RJ. Acyl-CoA:diacylglycerol acyltransferase: Properties, physiological roles, metabolic engineering and intentional control. Prog Lipid Res 2022; 88:101181. [PMID: 35820474 DOI: 10.1016/j.plipres.2022.101181] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 05/31/2022] [Accepted: 07/04/2022] [Indexed: 12/15/2022]
Abstract
Acyl-CoA:diacylglycerol acyltransferase (DGAT, EC 2.3.1.20) catalyzes the last reaction in the acyl-CoA-dependent biosynthesis of triacylglycerol (TAG). DGAT activity resides mainly in membrane-bound DGAT1 and DGAT2 in eukaryotes and bifunctional wax ester synthase-diacylglycerol acyltransferase (WSD) in bacteria, which are all membrane-bound proteins but exhibit no sequence homology to each other. Recent studies also identified other DGAT enzymes such as the soluble DGAT3 and diacylglycerol acetyltransferase (EaDAcT), as well as enzymes with DGAT activities including defective in cuticular ridges (DCR) and steryl and phytyl ester synthases (PESs). This review comprehensively discusses research advances on DGATs in prokaryotes and eukaryotes with a focus on their biochemical properties, physiological roles, and biotechnological and therapeutic applications. The review begins with a discussion of DGAT assay methods, followed by a systematic discussion of TAG biosynthesis and the properties and physiological role of DGATs. Thereafter, the review discusses the three-dimensional structure and insights into mechanism of action of human DGAT1, and the modeled DGAT1 from Brassica napus. The review then examines metabolic engineering strategies involving manipulation of DGAT, followed by a discussion of its therapeutic applications. DGAT in relation to improvement of livestock traits is also discussed along with DGATs in various other eukaryotic organisms.
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Affiliation(s)
- Guanqun Chen
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6H 2P5, Canada.
| | - John L Harwood
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK
| | - M Joanne Lemieux
- Department of Biochemistry, University of Alberta, Membrane Protein Disease Research Group, Edmonton T6G 2H7, Canada
| | - Scot J Stone
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada.
| | - Randall J Weselake
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6H 2P5, Canada
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6
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Huis In 't Veld RV, Lara P, Jager MJ, Koning RI, Ossendorp F, Cruz LJ. M1-derived extracellular vesicles enhance photodynamic therapy and promote immunological memory in preclinical models of colon cancer. J Nanobiotechnology 2022; 20:252. [PMID: 35658868 PMCID: PMC9164362 DOI: 10.1186/s12951-022-01448-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 05/01/2022] [Indexed: 12/15/2022] Open
Abstract
Extracellular vesicles (EVs) are promising drug carriers of photosensitizers for photodynamic therapy (PDT) in cancer treatment, due to their ability to circulate in blood and enter cells efficiently. The therapeutic potential of EVs has been suggested to depend on the type and physiological state of their cell of origin. However, the effects of deriving EVs from various cells in different physiological states on their antitumor capacity are rarely evaluated. In the present study, we compared the antitumor efficacy of EV-mediated PDT by incorporating the photosensitizer Zinc Phthalocyanine (ZnPc) into EVs from multiple cells sources. ZnPc was incorporated by a direct incubation strategy into EVs derived from immune cells (M1-like macrophages and M2-like macrophages), cancer cells (B16F10 melanoma cancer cells) and external sources (milk). Our data show that all EVs are suitable carriers for ZnPc and enable efficient PDT in vitro in co-culture models and in vivo. We observed that EV-mediated PDT initiates immunogenic cell death through the release and exposure of damage associated molecular patterns (DAMPs) on cancer cells, which subsequently induced dendritic cell (DC) maturation. Importantly, of all ZnPc-EVs tested, in absence of light only M1-ZnPc displayed toxicity to MC38, but not to DC, in monoculture and in co-culture, indicating specificity for cancer over immune cells. In MC38 tumor-bearing mice, only M1-ZnPc induced a tumor growth delay compared to control in absence of light. Interestingly, M1- but not M2-mediated PDT, induced complete responses against MC38 tumors in murine models (100% versus 38% of cases, respectively), with survival of all animals up to at least 60 days post inoculation. Finally, we show that all cured animals are protected from a rechallenge with MC38 cells, suggesting the induction of immunological memory after EV-mediated PDT. Together, our data show the importance of the cell type from which the EVs are obtained and highlight the impact of the immunological state of these cells on the antitumor efficacy of EV-mediated PDT.
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Affiliation(s)
- Ruben V Huis In 't Veld
- Department of Radiology, Leiden University Medical Centre (LUMC), Room C2-187h, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands.,Department of Ophthalmology, Leiden University Medical Centre (LUMC), Leiden, The Netherlands
| | - Pablo Lara
- Department of Radiology, Leiden University Medical Centre (LUMC), Room C2-187h, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Martine J Jager
- Department of Ophthalmology, Leiden University Medical Centre (LUMC), Leiden, The Netherlands
| | - Roman I Koning
- Department of Cell and Chemical Biology, Section Electron Microscopy, Leiden University Medical Centre (LUMC), Leiden, The Netherlands
| | - Ferry Ossendorp
- Department of Immunology, Leiden University Medical Centre (LUMC), Leiden, The Netherlands
| | - Luis J Cruz
- Department of Radiology, Leiden University Medical Centre (LUMC), Room C2-187h, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands.
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7
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Bhunia RK, Sinha K, Chawla K, Randhawa V, Sharma TR. Functional characterization of two type-1 diacylglycerol acyltransferase (DGAT1) genes from rice (Oryza sativa) embryo restoring the triacylglycerol accumulation in yeast. PLANT MOLECULAR BIOLOGY 2021; 105:247-262. [PMID: 33089420 DOI: 10.1007/s11103-020-01085-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 10/13/2020] [Indexed: 06/11/2023]
Abstract
Two OsDGAT1 genes showed the ability to restore TAG and LB synthesis in yeast H1246. Alterations in the N-terminal region of OsDGAT1-1 gene revealed its regulatory role in gene function. Accumulation of triacylglycerol (TAG) or oil in vegetative tissues has emerged as a promising approach to meet the global needs of food, feed, and fuel. Rice (Oryza sativa) has been recognized as an important cereal crop containing nutritional rice bran oil with high economic value for renewable energy production. To identify the key component involved in storage lipid biosynthesis, two type-1 diacylglycerol acyltransferases (DGAT1) from rice were characterized for its in vivo function in the H1246 (dga1, lro1, are1 and are2) yeast quadruple mutant. The ectopic expression of rice DGAT1 (designated as OsDGAT1-1 and OsDGAT1-2) genes restored the capability of TAG synthesis and lipid body (LB) formation in H1246. OsDGAT1-1 showed nearly equal substrate preferences to C16:0-CoA and 18:1-CoA whereas OsDGAT1-2 displayed substrate selectivity for C16:0-CoA over 18:1-CoA, indicating that these enzymes have contrasting substrate specificities. In parallel, we have identified the intrinsically disordered region (IDR) at the N-terminal domains of OsDGAT1 proteins. The regulatory role of the N-terminal domain was dissected. Single point mutations at the phosphorylation sites and truncations of the N-terminal region highlighted reduced lipid accumulation capabilities among different OsDGAT1-1 variants.
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Affiliation(s)
- Rupam Kumar Bhunia
- Plant Tissue Culture and Genetic Engineering, National Agri-Food Biotechnology Institute (NABI), Mohali, Punjab, 140306, India.
| | - Kshitija Sinha
- Plant Tissue Culture and Genetic Engineering, National Agri-Food Biotechnology Institute (NABI), Mohali, Punjab, 140306, India
| | - Kirti Chawla
- Plant Tissue Culture and Genetic Engineering, National Agri-Food Biotechnology Institute (NABI), Mohali, Punjab, 140306, India
| | - Vinay Randhawa
- Department of Biochemistry, Panjab University, Chandigarh, 160014, India
| | - Tilak Raj Sharma
- Plant Tissue Culture and Genetic Engineering, National Agri-Food Biotechnology Institute (NABI), Mohali, Punjab, 140306, India
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8
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Chawla K, Sinha K, Kaur R, Bhunia RK. Identification and functional characterization of two acyl CoA:diacylglycerol acyltransferase 1 (DGAT1) genes from forage sorghum (Sorghum bicolor) embryo. PHYTOCHEMISTRY 2020; 176:112405. [PMID: 32473393 DOI: 10.1016/j.phytochem.2020.112405] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 03/31/2020] [Accepted: 05/13/2020] [Indexed: 06/11/2023]
Abstract
Elevating the lipid content in high-biomass forage crops has emerged as a new research platform for increasing energy density and improving livestock production efficiency associated with improved human health beneficial meat and milk quality. To gain insights of triacylglycerol (TAG) biosynthesis in forage sorghum, two type-1 diacylglycerol acyltransferase (designated as SbDGAT1-1 and SbDGAT1-2) were characterized for its in vivo function. SbDGAT1-2 is more abundantly expressed in embryo and bran during the early stage of the grain development in comparison to SbDGAT1-1. Heterologous expression of SbDGAT1 genes in TAG deficient H1246 strain restored the TAG accumulation capability with high substrate predilection towards 16:0, 16:1 and 18:1 fatty acids (FA). In parallel, we have identified N-terminal intrinsically disordered region (IDR) in SbDGAT1 proteins. To test the efficacy of the N-terminal region, truncated variants of SbDGAT1-1 (designated as SbDGAT1-1(39-515) and SbDGAT1-1(89-515)) were generated and expressed in yeast H1246 strain. Deletion in the N-terminal region resulted in decreased accumulation of TAG and FA (16:0 and 18:0) when compared to the SbDGAT1-1 variant expressed in yeast H1246 strain. The present study provides significant insight in forage sorghum DGAT1 gene function, useful for enhancing the green-forage TAG content through metabolic engineering.
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Affiliation(s)
- Kirti Chawla
- Plant Tissue Culture and Genetic Engineering, National Agri-Food Biotechnology Institute (NABI), Mohali, 140306, Punjab, India
| | - Kshitija Sinha
- Plant Tissue Culture and Genetic Engineering, National Agri-Food Biotechnology Institute (NABI), Mohali, 140306, Punjab, India
| | - Ranjeet Kaur
- Department of Genetics, University of Delhi South Campus, New Delhi, 110026, India
| | - Rupam Kumar Bhunia
- Plant Tissue Culture and Genetic Engineering, National Agri-Food Biotechnology Institute (NABI), Mohali, 140306, Punjab, India.
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9
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Sui X, Wang K, Gluchowski NL, Elliott SD, Liao M, Walther TC, Farese RV. Structure and catalytic mechanism of a human triacylglycerol-synthesis enzyme. Nature 2020; 581:323-328. [PMID: 32433611 PMCID: PMC7398557 DOI: 10.1038/s41586-020-2289-6] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 03/17/2020] [Indexed: 12/12/2022]
Abstract
Triglycerides (triacylglycerols, TGs) store metabolic energy in organisms and have industrial uses for foods and fuels. Excessive accumulation of TGs in humans causes obesity and is associated with metabolic diseases1. TG synthesis is catalyzed by acyl-CoA:diacylglycerol acyltransferase (DGAT) enzymes2–4 whose structures and catalytic mechanisms are unknown. Here we determined the structure of dimeric human DGAT1, a member of the membrane-bound O-acyltransferase (MBOAT) family, by cryo-electron microscopy at 3.0-Å resolution. DGAT1 forms a homodimer through N-terminal segments and a hydrophobic interface, with putative active sites within the membrane region. A structure obtained with oleoyl-CoA substrate resolved at 3.2-Å shows that the CoA moiety binds DGAT1 on the cytosolic side and the acyl group lies deep within a hydrophobic channel, positioning the acyl-CoA thioester bond near an invariant catalytic histidine residue. The reaction center is located inside a large cavity, which opens laterally to the membrane bilayer, providing lipid access to the active site. A lipid-like density, possibly an acyl-acceptor molecule, is located within the reaction center, orthogonal to acyl-CoA. Insights provided by the DGAT1 structures, together with mutagenesis and functional studies, give rise to a model of catalysis for DGAT’s generation of TGs.
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Affiliation(s)
- Xuewu Sui
- Department of Molecular Metabolism, Harvard T. H. Chan School of Public Health, Boston, MA, USA.,Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Kun Wang
- Department of Molecular Metabolism, Harvard T. H. Chan School of Public Health, Boston, MA, USA.,Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Nina L Gluchowski
- Department of Molecular Metabolism, Harvard T. H. Chan School of Public Health, Boston, MA, USA.,Department of Cell Biology, Harvard Medical School, Boston, MA, USA.,Department of Gastroenterology, Hepatology, and Nutrition, Boston Children's Hospital, Boston, MA, USA
| | - Shane D Elliott
- Department of Molecular Metabolism, Harvard T. H. Chan School of Public Health, Boston, MA, USA.,Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Maofu Liao
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA.
| | - Tobias C Walther
- Department of Molecular Metabolism, Harvard T. H. Chan School of Public Health, Boston, MA, USA. .,Department of Cell Biology, Harvard Medical School, Boston, MA, USA. .,Broad Institute of MIT and Harvard, Cambridge, MA, USA. .,Howard Hughes Medical Institute, Boston, MA, USA.
| | - Robert V Farese
- Department of Molecular Metabolism, Harvard T. H. Chan School of Public Health, Boston, MA, USA. .,Department of Cell Biology, Harvard Medical School, Boston, MA, USA. .,Broad Institute of MIT and Harvard, Cambridge, MA, USA.
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10
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Wang L, Qian H, Nian Y, Han Y, Ren Z, Zhang H, Hu L, Prasad BVV, Laganowsky A, Yan N, Zhou M. Structure and mechanism of human diacylglycerol O-acyltransferase 1. Nature 2020; 581:329-332. [PMID: 32433610 PMCID: PMC7255049 DOI: 10.1038/s41586-020-2280-2] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 03/17/2020] [Indexed: 12/27/2022]
Abstract
Diacylglycerol O-acyltransferase-1 (DGAT1) synthesizes triacylglycerides and is required for dietary fat absorption and fat storage in humans1. DGAT1 belongs to the superfamily of membrane-bound O-acyltransferases (MBOAT) that are found in all kingdoms of life and involved in acylation of lipids and proteins2,3. It remains unclear how human DGAT1 (hDGAT1) or other mammalian members of the MBOAT family recognize their substrates and catalyze their reactions. The absence of three-dimensional structures also hampers rational targeting of hDGAT1 for therapeutic purposes. Here we present the structure of hDGAT1 in complex with a substrate oleoyl Coenzyme A solved by cryo-electron microscopy. Each hDGAT1 protomer has nine transmembrane helices and eight of which form a conserved structural fold that we define as the MBOAT fold. The MBOAT fold in hDGAT1 carves out a hollow chamber in the membrane that encloses highly conserved catalytic residues. The chamber has separate entrances for the two substrates fatty acyl Coenzyme A and diacylglycerol. hDGAT1 can exist as either a homodimer or homotetramer and the two forms have similar enzymatic activity. The N-terminus of hDGAT1 interacts with the neighboring protomer and these interactions are required for the enzymatic activity.
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Affiliation(s)
- Lie Wang
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Hongwu Qian
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Yin Nian
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA.,Ion Channel Research and Drug Development Center, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Yimo Han
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA.,Department of Material Science and Nanoengineering, Rice University, Houston, TX, USA
| | - Zhenning Ren
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Hanzhi Zhang
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Liya Hu
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
| | - B V Venkataram Prasad
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Arthur Laganowsky
- Department of Chemistry, Texas A&M University, College Station, TX, USA
| | - Nieng Yan
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA.
| | - Ming Zhou
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA.
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