Bacillus velezensis strain GH1-13 contains a (2R,3R)-butanediol
dehydrogenase (R-BDH) BdhA which converts acetoin
to R-BD reversibly, however, little is known about its regulatory
cysteine and biological significance. We performed sitedirected
mutation of three cysteines in BdhA. The C37S mutant
had no enzyme activity and the C34S and C177S mutants
differed from each other and wild type (WT). After zinc affinity
chromatography, 1 mM ZnCl2 treatment resulted in a
3-fold enhancement of the WT activity, but reduced activity
of the C34S mutant by more than 2 folds compared to the untreated
ones. However, ZnCl2 treatment did not affect the activity
of the C177S mutant. Most of the double and triple mutant
proteins (C34S/C37S, C34S/C177S, C37S/C177S, and
C34S/C37S/C177S) were aggregated in zinc resins, likely due
to the decreased protein stability. All of the purified WT and
single mutant proteins increased multiple intermolecular disulfide
bonds in the presence of H2O2 as the buffer pH decreased
from 7.5 to 5.5, whereas an intramolecular disulfide
bond of cysteine 177 and another cysteine in the CGIC motif
region was likely formed at pH higher than pKa of 7.5. When
pH varied, WT and its C34S or C177S mutants reduced acetoin
to R-BD at the optimum pH 5.5 and oxidized R-BD to
acetoin at the optimum pH 10. This study demonstrated that
cysteine residues in BdhA play a regulatory role for the production
of acetoin and R-BD depending on pH as well as
metal binding and oxidative stress.
Citations
Citations to this article as recorded by
Significantly enhanced specific activity of Bacillus subtilis (2,3)-butanediol dehydrogenase through computer-aided refinement of its substrate-binding pocket Bochun Hu, Xiaoqi Xi, Fugang Xiao, Xiaomeng Bai, Yuanyuan Gong, Yifan Li, Xueqin Qiao, Cunduo Tang, Jihong Huang International Journal of Biological Macromolecules.2024; 281: 136443. CrossRef
Structural and enzymatic characterization of Bacillus subtilis R,R-2,3-butanediol dehydrogenase Xiaofei Wang, Lingyun Jia, Fangling Ji Biochimica et Biophysica Acta (BBA) - General Subjects.2023; 1867(4): 130326. CrossRef
Engineering a BsBDHA substrate-binding pocket entrance for the improvement in catalytic performance toward (R)-phenyl-1,2-ethanediol based on the computer-aided design Bo-Chun Hu, Meng-Ran Li, Ying-Ying Li, Xin-Shuang Yuan, Yu-Ye Hu, Fu-Gang Xiao Biochemical Engineering Journal.2023; 194: 108907. CrossRef
Thermococcus onnurineus NA1, an obligate anaerobic hyperthermophilic
archaeon, showed variable oxygen (O2) sensitivity
depending on the types of substrate employed as an
energy source. Unexpectedly, the culture with yeast extract
as a sole energy source showed enhanced growth by 2-fold
in the presence of O2. Genome-wide transcriptome analysis
revealed the upregulation of several antioxidant-related genes
encoding thioredoxin peroxidase (TON_0862), rubrerythrin
(TON_0864), rubrerythrin-related protein (TON_0873),
NAD(P)H rubredoxin oxidoreductase (TON_0865), or thioredoxin
reductase (TON_1603), which can couple the detoxification
of reactive oxygen species with the regeneration
of NAD(P)+ from NAD(P)H. We present a plausible mechanism
by which O2 serves to maintain the intracellular redox
balance. This study demonstrates an unusual strategy of an
obligate anaerobe underlying O2-mediated growth enhancement
despite not having heme-based or cytochrome-type
proteins.
Citations
Citations to this article as recorded by
How low can they go? Aerobic respiration by microorganisms under apparent anoxia Jasmine S Berg, Soeren Ahmerkamp, Petra Pjevac, Bela Hausmann, Jana Milucka, Marcel M M Kuypers FEMS Microbiology Reviews.2022;[Epub] CrossRef
Reductive evolution and unique predatory mode in the CPR bacterium Vampirococcus lugosii David Moreira, Yvan Zivanovic, Ana I. López-Archilla, Miguel Iniesto, Purificación López-García Nature Communications.2021;[Epub] CrossRef