1
|
Diez V, Loznik M, Taylor S, Winn M, Rattray NJW, Podmore H, Micklefield J, Goodacre R, Medema MH, Müller U, Bovenberg R, Janssen DB, Takano E. Functional Exchangeability of Oxidase and Dehydrogenase Reactions in the Biosynthesis of Hydroxyphenylglycine, a Nonribosomal Peptide Building Block. ACS Synth Biol 2015; 4:796-807. [PMID: 25713978 DOI: 10.1021/sb500368w] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A key problem in the engineering of pathways for the production of pharmaceutical compounds is the limited diversity of biosynthetic enzymes, which restricts the attainability of suitable traits such as less harmful byproducts, enhanced expression features, or different cofactor requirements. A promising synthetic biology approach is to redesign the biosynthetic pathway by replacing the native enzymes by heterologous proteins from unrelated pathways. In this study, we applied this method to effectively re-engineer the biosynthesis of hydroxyphenylglycine (HPG), a building block for the calcium-dependent antibiotic of Streptomyces coelicolor, a nonribosomal peptide. A key step in HPG biosynthesis is the conversion of 4-hydroxymandelate to 4-hydroxyphenylglyoxylate, catalyzed by hydroxymandelate oxidase (HmO), with concomitant generation of H2O2. The same reaction can also be catalyzed by O2-independent mandelate dehydrogenase (MdlB), which is a catabolic enzyme involved in bacterial mandelate utilization. In this work, we engineered alternative HPG biosynthetic pathways by replacing the native HmO in S. coelicolor by both heterologous oxidases and MdlB dehydrogenases from various sources and confirmed the restoration of calcium-dependent antibiotic biosynthesis by biological and UHPLC-MS analysis. The alternative enzymes were isolated and kinetically characterized, confirming their divergent substrate specificities and catalytic mechanisms. These results demonstrate that heterologous enzymes with different physiological contexts can be used in a Streptomyces host to provide an expanded library of enzymatic reactions for a synthetic biology approach. This study thus broadens the options for the engineering of antibiotic production by using enzymes with different catalytic and structural features.
Collapse
Affiliation(s)
| | | | | | | | | | - Helen Podmore
- ThermoFisher Scientific, 1 Boundary
Way, Hemel Hempstead, Herts, HP2 7GE, United Kingdom
| | | | | | | | - Ulrike Müller
- DSM Biotechnology Center, R&D, P.O. Box 1, 2600 AM Delft, The Netherlands
| | - Roel Bovenberg
- DSM Biotechnology Center, R&D, P.O. Box 1, 2600 AM Delft, The Netherlands
| | | | | |
Collapse
|
2
|
Xue YP, Zheng YG, Liu ZQ, Liu X, Huang JF, Shen YC. Efficient Synthesis of Non-Natural l-2-Aryl-Amino Acids by a Chemoenzymatic Route. ACS Catal 2014. [DOI: 10.1021/cs500535d] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ya-Ping Xue
- Institute
of Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China
- Engineering
Research Center of Bioconversion and Biopurification of Ministry of
Education, Zhejiang University of Technology, Hangzhou 310014, China
| | - Yu-Guo Zheng
- Institute
of Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China
- Engineering
Research Center of Bioconversion and Biopurification of Ministry of
Education, Zhejiang University of Technology, Hangzhou 310014, China
| | - Zhi-Qiang Liu
- Institute
of Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China
- Engineering
Research Center of Bioconversion and Biopurification of Ministry of
Education, Zhejiang University of Technology, Hangzhou 310014, China
| | - Xue Liu
- Institute
of Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China
- Engineering
Research Center of Bioconversion and Biopurification of Ministry of
Education, Zhejiang University of Technology, Hangzhou 310014, China
| | - Jian-Feng Huang
- Institute
of Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China
- Engineering
Research Center of Bioconversion and Biopurification of Ministry of
Education, Zhejiang University of Technology, Hangzhou 310014, China
| | - Yin-Chu Shen
- Institute
of Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China
- Engineering
Research Center of Bioconversion and Biopurification of Ministry of
Education, Zhejiang University of Technology, Hangzhou 310014, China
| |
Collapse
|
3
|
Ohshiro H, Mitsui K, Ando N, Ohsawa Y, Koinuma W, Takahashi H, Kondo SI, Nabeshima T, Yano Y. Oxidation-active flavin models: oxidation of alpha-hydroxy acids by benzo-dipteridine bearing metal-binding site in the presence of divalent metal ion and base in organic solvents. J Am Chem Soc 2001; 123:2478-86. [PMID: 11456915 DOI: 10.1021/ja0009121] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The oxidizing ability of benzo-dipteridine bearing a bipyridin-6-ylmethyl moiety (4) was found to be increased with Zn(2+) by approximately 10(3)-fold for sulfite addition in MeOH and approximately 10(2)-fold for oxidation of an NADH model in MeCN. It was found for the first time that 4 is able to oxidize alpha-hydroxy acids to alpha-keto acids in the presence of a divalent metal ion such as Zn(2+), Co(2+), and Ni(2+) and an amine base in MeCN or t-BuOH, whereas benzo-dipteridine having a bipyridin-5-ylmethyl moiety (3) is unable to oxidize them under the same conditions. The oxidation reaction was kinetically investigated including the kinetic isotope effect for deuterated mandelic acids (k(H)/k(D) = 2.1-3.7) and the Hammett plots for substituted mandelic acids (V-shaped plots). In the reaction of alpha-substituted alpha-hydroxy acids such as alpha-methyl mandelic and benzylic acids with 4, novel oxidative decarboxylation was found to take place, giving acetophenone and benzophenone, respectively. The oxidation mechanism for mandelic acid was proposed to proceed via a ternary complex of 4.Zn(2+).PhCH(OH)CO(2)(-), in which alpha-oxyanion of mandelate attacks C(4a)-position of 4 to form an adduct followed by 1,2-elimination to afford benzoyl formate and 2e-reduced 4. The roles of the metal ion were proposed as follows; (i) activation of 4, (ii) substrate-binding site, and (iii) activation of the bound alpha-hydroxy acid by lowering pK(a)'s of alpha-OH and alpha-CH. This is a first example that a flavin model oxidizes alpha-hydroxy acids in the presence of a metal ion.
Collapse
Affiliation(s)
- H Ohshiro
- Department of Chemistry, Gunma University, Kiryu, Gunma 376-8515, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
4
|
Illias RM, Sinclair R, Robertson D, Neu A, Chapman SK, Reid GA. L-Mandelate dehydrogenase from Rhodotorula graminis: cloning, sequencing and kinetic characterization of the recombinant enzyme and its independently expressed flavin domain. Biochem J 1998; 333 ( Pt 1):107-15. [PMID: 9639569 PMCID: PMC1219562 DOI: 10.1042/bj3330107] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The l-mandelate dehydrogenase (L-MDH) from the yeast Rhodotorula graminis is a mitochondrial flavocytochrome b2 which catalyses the oxidation of mandelate to phenylglyoxylate coupled with the reduction of cytochrome c. We have used the N-terminal sequence of the enzyme to isolate the gene encoding this enzyme using the PCR. Comparison of the genomic sequence with the sequence of cDNA prepared by reverse transcription PCR revealed the presence of 11 introns in the coding region. The predicted amino acid sequence indicates a close relationship with the flavocytochromes b2 from Saccharomyces cerevisiae and Hansenula anomala, with about 40% identity to each. The sequence shows that a key residue for substrate specificity in S. cerevisiae flavocytochrome b2, Leu-230, is replaced by Gly in L-MDH. This substitution is likely to play an important part in determining the different substrate specificities of the two enzymes. We have developed an expression system and purification protocol for recombinant L-MDH. In addition, we have expressed and purified the flavin-containing domain of L-MDH independently of its cytochrome domain. Detailed steady-state and pre-steady-state kinetic investigations of both L-MDH and its independently expressed flavin domain have been carried out. These indicate that L-MDH is efficient with both physiological (cytochrome c, kcat=225 s-1 at 25 degrees C) and artificial (ferricyanide, kcat=550 s-1 at 25 degrees C) electron acceptors. Kinetic isotope effects with [2-2H]mandelate indicate that H-C-2 bond cleavage contributes somewhat to rate-limitation. However, the value of the isotope effect erodes significantly as the catalytic cycle proceeds. Reduction potentials at 25 degrees C were measured as -120 mV for the 2-electron reduction of the flavin and -10 mV for the 1-electron reduction of the haem. The general trends seen in the kinetic studies show marked similarities to those observed previously with the flavocytochrome b2 (L-lactate dehydrogenase) from S. cerevisiae.
Collapse
Affiliation(s)
- R M Illias
- Institute of Cell and Molecular Biology, University of Edinburgh, Mayfield Road, Edinburgh EH9 3JR, Scotland, U.K
| | | | | | | | | | | |
Collapse
|
5
|
Al-Shawi MK, Ketchum CJ, Nakamoto RK. The Escherichia coli FOF1 gammaM23K uncoupling mutant has a higher K0.5 for Pi. Transition state analysis of this mutant and others reveals that synthesis and hydrolysis utilize the same kinetic pathway. Biochemistry 1997; 36:12961-9. [PMID: 9335556 DOI: 10.1021/bi971478r] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The Escherichia coli FOF1 ATP synthase uncoupling mutation, gammaM23K, was found to increase the energy of interaction between gamma and beta subunits, prevent the proper utilization of binding energy to drive catalysis, and block the enzyme in a Pi release mode. In this paper, the effects of this mutation on substrate binding in cooperative ATP synthesis are assessed. Activation of ATP synthesis by ADP and Pi was determined for the gammaM23K FOF1. The K0.5 for ADP was not affected, but K0.5 for Pi was approximately 7-fold higher even though the apparent Vmax was close to the wild-type level. Wild-type enzyme had a turnover number of 82 s-1 at pH 7.5 and 30 degrees C. During oxidative phosphorylation, the apparent dissociation constant (KI) for ATP was not affected and was 5-6 mM for both wild-type and gammaM23K enzymes. Thus, the apparent binding affinity for ATP in the presence of DeltamuH+ was lowered by 7 orders of magnitude from the affinity measured at the high-affinity catalytic site. Arrhenius analysis of ATP synthesis for the gammaM23K FOF1 revealed that, like those of ATP hydrolysis, the transition state DeltaH was much more positive and TDeltaS was much less negative, adding up to little change in DeltaG. These results suggested that ATP synthesis is inefficient because of an extra bond between gamma and beta subunits which must be broken to achieve the transition state. Analysis of the transition state structures using isokinetic plots demonstrate that ATP hydrolysis and synthesis utilize the same kinetic pathway. Incorporating this information into a model for rotational catalysis suggests that at saturating substrate concentrations, the rate-limiting step for hydrolysis and synthesis is the rotational power stroke where each of the beta subunits changes conformation and affinity for nucleotide.
Collapse
Affiliation(s)
- M K Al-Shawi
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia 22906-0011, USA
| | | | | |
Collapse
|
6
|
Yorita K, Janko K, Aki K, Ghisla S, Palfey BA, Massey V. On the reaction mechanism of L-lactate oxidase: quantitative structure-activity analysis of the reaction with para-substituted L-mandelates. Proc Natl Acad Sci U S A 1997; 94:9590-5. [PMID: 9275167 PMCID: PMC23227 DOI: 10.1073/pnas.94.18.9590] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The rate constants for reduction of the flavoenzyme, L-lactate oxidase, and a mutant (in which alanine 95 is replaced by glycine), by a series of para-substituted mandelates, in both the 2-1H- and 2-2H- forms, have been measured by rapid reaction spectrophotometry. In all cases, significant isotope effects (1H/2H = 3-7) on the rate constants of flavin reduction were found, indicating that flavin reduction is a direct measure of alpha-C-H bond breakage. The rate constants show only a small influence of the electronic characteristics of the substituents, but show a good correlation when combined with some substituent volume parameters. A surprisingly good correlation is found with the molecular mass of the substrate. The results are compatible with any mechanism in which there is little development of charge in the transition state. This could be a transfer of hydride to the flavin N(5) position or a synchronous mechanism in which the alpha-C-H is formally abstracted as a H+ while the resulting charge is simultaneously neutralized by another event.
Collapse
Affiliation(s)
- K Yorita
- Institute for Enzyme Research, University of Tokushima, Kuramoto-cho 3-18-15, Tokushima 770, Japan
| | | | | | | | | | | |
Collapse
|