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Pérez-Burgos M, Søgaard-Andersen L. Biosynthesis and function of cell-surface polysaccharides in the social bacterium Myxococcus xanthus. Biol Chem 2021; 401:1375-1387. [PMID: 32769218 DOI: 10.1515/hsz-2020-0217] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 08/04/2020] [Indexed: 12/29/2022]
Abstract
In bacteria, cell-surface polysaccharides fulfill important physiological functions, including interactions with the environment and other cells as well as protection from diverse stresses. The Gram-negative delta-proteobacterium Myxococcus xanthus is a model to study social behaviors in bacteria. M. xanthus synthesizes four cell-surface polysaccharides, i.e., exopolysaccharide (EPS), biosurfactant polysaccharide (BPS), spore coat polysaccharide, and O-antigen. Here, we describe recent progress in elucidating the three Wzx/Wzy-dependent pathways for EPS, BPS and spore coat polysaccharide biosynthesis and the ABC transporter-dependent pathway for O-antigen biosynthesis. Moreover, we describe the functions of these four cell-surface polysaccharides in the social life cycle of M. xanthus.
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Affiliation(s)
- María Pérez-Burgos
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch Str. 10, D-35043 Marburg, Germany
| | - Lotte Søgaard-Andersen
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch Str. 10, D-35043 Marburg, Germany
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Izzat S, Rachid S, Ajdidi A, El-Nakady YA, Liu XX, Ye BC, Müller R. The ROK like protein of Myxococcus xanthus DK1622 acts as a pleiotropic transcriptional regulator for secondary metabolism. J Biotechnol 2020; 311:25-34. [PMID: 32057784 DOI: 10.1016/j.jbiotec.2020.02.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 02/03/2020] [Accepted: 02/10/2020] [Indexed: 11/17/2022]
Abstract
Myxococcus xanthus DK1622 is known as a proficient producer of different kinds of secondary metabolites (SM) with various biological activities, including myxovirescin A, myxalamide A, myxochromide A and DKxanthene. Low production of SM in the wild type bacteria makes searching for production optimization methods highly desirable. Identification and induction of endogenous key molecular feature(s) regulating the production level of the metabolites remain promising, while heterologous expression of the biosynthetic genes is not always efficient because of various complicating factors including codon usage bias. This study established proteomic and molecular approaches to elucidate the regulatory roles of the ROK regulatory protein in the modification of secondary metabolite biosynthesis. Interestingly, the results revealed that rok inactivation significantly reduced the production of the SM and also changed the motility in the bacteria. Electrophoretic mobility shift assay using purified ROK protein indicated a direct enhancement of the promoters encoding transcription of the DKxanthene, myxochelin A, and myxalamide A biosynthesis machinery. Comparative proteomic analysis by two-dimensional fluorescence difference in-gel electrophoresis (2D-DIGE) was employed to identify the protein profiles of the wild type and rok mutant strains during early and late logarithmic growth phases of the bacterial culture. Resulting data demonstrated overall 130 differently altered proteins by the effect of the rok gene mutation, including putative proteins suspected to be involved in transcriptional regulation, carbohydrate metabolism, development, spore formation, and motility. Except for a slight induction seen in the production of myxovirescin A in a rok over-expression background, no changes were found in the formation of the other SM. From the outcome of our investigation, it is possible to conclude that ROK acts as a pleiotropic regulator of secondary metabolite formation and development in M. xanthus, while its direct effects still remain speculative. More experiments are required to elucidate in detail the variable regulation effects of the protein and to explore applicable approaches for generating valuable SM in this bacterium.
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Affiliation(s)
- Selar Izzat
- Department of Biology, School of Science and Health, Koya University, Koysinjaq, Kurdistan Region, Iraq
| | - Shwan Rachid
- Charmo Research Center, Charmo University, 46023 Chamchamal-Sulaimani, Iraq; Department of Microbial Natural Products, Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Center for Infection Research (HZI) and Department of Pharmacy at Saarland University, Campus E8.1, 66123 Saarbrücken, Germany.
| | - Ahmad Ajdidi
- Department of Microbial Natural Products, Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Center for Infection Research (HZI) and Department of Pharmacy at Saarland University, Campus E8.1, 66123 Saarbrücken, Germany
| | - Yasser A El-Nakady
- Department of Microbial Natural Products, Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Center for Infection Research (HZI) and Department of Pharmacy at Saarland University, Campus E8.1, 66123 Saarbrücken, Germany; Zoology Department, College of Science, King Saud University, P.O. Box 2455, 11415 Riyadh - Saudi Arabia
| | - Xin-Xin Liu
- Lab of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Bang-Ce Ye
- Lab of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Rolf Müller
- Department of Microbial Natural Products, Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Center for Infection Research (HZI) and Department of Pharmacy at Saarland University, Campus E8.1, 66123 Saarbrücken, Germany.
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Pan H, Luan J, He X, Lux R, Shi W. The clpB gene is involved in the stress response of Myxococcus xanthus during vegetative growth and development. MICROBIOLOGY-SGM 2012; 158:2336-2343. [PMID: 22790397 DOI: 10.1099/mic.0.060103-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The Clp/HSP100 family of molecular chaperones is ubiquitous in both prokaryotes and eukaryotes. These proteins play important roles in refolding, disaggregating and degrading proteins damaged by stress. As a subclass of the Clp/HSP100 family, ClpB has been shown to be involved in various stress responses as well as other functions in bacteria. In the present study, we investigated the role of a predicted ClpB-encoding gene, MXAN5092, in the stress response during vegetative growth and development of Myxococcus xanthus. Transcriptional analysis confirmed induction of this clpB homologue under different stress conditions, and further phenotypic analysis revealed that an in-frame deletion mutant of MXAN5092 was more sensitive to various stress treatments than the wild-type strain during vegetative growth. Moreover, the absence of the MXAN5092 gene resulted in decreased heat tolerance of myxospores, indicating the involvement of this clpB homologue in the stress response during the development of myxospores. The M. xanthus recombinant ClpB (MXAN5092) protein also showed a general chaperone activity in vitro. Overall, our genetic and phenotypic analysis of the predicted ATP-dependent chaperone protein ClpB (MXAN5092) demonstrated that it functions as a chaperone protein and plays an important role in cellular stress tolerance during both vegetative growth and development of M. xanthus.
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Affiliation(s)
- Hongwei Pan
- School of Dentistry, University of California, Los Angeles, CA 90095, USA
| | - Jia Luan
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, CA 90095, USA
| | - Xuesong He
- School of Dentistry, University of California, Los Angeles, CA 90095, USA
| | - Renate Lux
- School of Dentistry, University of California, Los Angeles, CA 90095, USA
| | - Wenyuan Shi
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, CA 90095, USA.,School of Dentistry, University of California, Los Angeles, CA 90095, USA
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