scholarly journals Investigating the roles of putative active site residues in the oxalate decarboxylase from Bacillus subtilis

2007 ◽  
Vol 464 (1) ◽  
pp. 36-47 ◽  
Author(s):  
Draženka Svedružić ◽  
Yong Liu ◽  
Laurie A. Reinhardt ◽  
Ewa Wroclawska ◽  
W. Wallace Cleland ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Active Site ◽  
Active Site Residues ◽  
Oxalate Decarboxylase ◽  
Putative Active Site

Identification of the active site and characterization of a novel sporulation-specific cysteine protease YabG from Bacillus subtilis

2021 ◽  
Author(s):  
Ryuji Yamazawa ◽  
Ritsuko Kuwana ◽  
Kenji Takeuchi ◽  
Hiromu Takamatsu ◽  
Yoshitaka Nakajima ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Chemical Modification ◽  
Cysteine Protease ◽  
Active Site ◽  
Amino Acid Sequences ◽  
Site Directed Mutagenesis ◽  
Protease Gene ◽  
Active Site Residues ◽  
Protein Determination ◽  
35 Kda Protein

Abstract In order to characterize the probable protease gene yabG found in the genomes of spore-forming bacteria, Bacillus subtilis yabG was expressed as a 35 kDa His-tagged protein (BsYabG) in Escherichia coli cells. During purification using Ni-affinity chromatography, the 35 kDa protein was degraded via several intermediates to form a 24 kDa protein. Furthermore, it was degraded after an extended incubation period. The effect of protease inhibitors, including certain chemical modification reagents, on the conversion of the 35 kDa protein to the 24 kDa protein was investigated. Reagents reacting with sulfhydryl groups exerted significant effects, strongly suggesting that the yabG gene product is a cysteine protease with autolytic activity. Site-directed mutagenesis of the conserved Cys and His residues indicated that Cys218 and His172 are active site residues. No degradation was observed in the C218A/S and H172A mutants. In addition to the chemical modification reagents, benzamidine inhibited the degradation of the 24 kDa protein. Determination of the N-terminal amino acid sequences of the intermediates revealed trypsin-like specificity for YabG protease. Based on the relative positions of His172 and Cys218 and their surrounding sequences, we propose the classification of YabG as a new family of clan CD in the Merops peptidase database.

Identification of Putative Active-site Residues in the DNase Domain of Colicin E9 by Random Mutagenesis

1996 ◽  
Vol 260 (5) ◽  
pp. 731-742 ◽  
Author(s):  
Carole Garinot-Schneider ◽  
Ansgar J. Pommer ◽  
Geoffrey R. Moore ◽  
Colin Kleanthous ◽  
Richard James
Keyword(s):  
Active Site ◽  
Random Mutagenesis ◽  
Active Site Residues ◽  
Putative Active Site ◽  
Colicin E9

scholarly journals Mutational Analysis of Active Site Residues Essential for Sensing of Organic Hydroperoxides by Bacillus subtilis OhrR

2007 ◽  
Vol 189 (19) ◽  
pp. 7069-7076 ◽  
Author(s):  
Sumarin Soonsanga ◽  
Mayuree Fuangthong ◽  
John D. Helmann
Keyword(s):  
Hydrogen Bond ◽  
Bacillus Subtilis ◽  
Conformational Changes ◽  
Active Site ◽  
Mutational Analysis ◽  
High Sensitivity ◽  
Oxidative Modification ◽  
Active Site Residues

ABSTRACT Bacillus subtilis OhrR is the prototype for the one-Cys family of organic peroxide-sensing regulatory proteins. Mutational analyses indicate that the high sensitivity of the active site cysteine (C15) to peroxidation requires three Tyr residues. Y29 and Y40 from the opposing subunit of the functional dimer hydrogen bond with the reactive Cys thiolate, and substitutions at these positions reduce or eliminate the ability of OhrR to respond to organic peroxides. Y19 is also critical for peroxide sensing, and the Ala substitution mutant (OhrR Y19A) is less susceptible to oxidation at the active site C15 in vivo. The Y19A protein also displays decreased sensitivity to peroxide-mediated oxidation in vitro. Y19 is in van der Waals contact with two residues critical for protein function, F16 and R23. The latter residue makes critical contact with the DNA backbone in the OhrR-operator complex. These results indicate that the high sensitivity of the OhrR C15 residue to oxidation requires interactions with the opposed Tyr residues. Oxidative modification of C15 likely disrupts the C15-Y29′-Y40′ hydrogen bond network and thereby initiates conformational changes that reduce the ability of OhrR to bind to its operator site.

Analysis of putative active site residues of the poliovirus 3C protease

Virology ◽  
1991 ◽  
Vol 181 (2) ◽  
pp. 609-619 ◽  
Author(s):  
Katherine M. Kean ◽  
Natalya L. Teterina ◽  
Daniel Marc ◽  
Marc Girard
Keyword(s):  
Active Site ◽  
Active Site Residues ◽  
3C Protease ◽  
Putative Active Site

scholarly journals The histone H3-H4 tetramer is a copper reductase enzyme

Science ◽  
2020 ◽  
Vol 369 (6499) ◽  
pp. 59-64 ◽  
Author(s):  
Narsis Attar ◽  
Oscar A. Campos ◽  
Maria Vogelauer ◽  
Chen Cheng ◽  
Yong Xue ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Active Site ◽  
Histone H3 ◽  
Copper Binding ◽  
Active Site Residues ◽  
Chromatin Compaction ◽  
Putative Active Site ◽  
Dimerization Interface ◽  
Cellular Copper

Eukaryotic histone H3-H4 tetramers contain a putative copper (Cu2+) binding site at the H3-H3′ dimerization interface with unknown function. The coincident emergence of eukaryotes with global oxygenation, which challenged cellular copper utilization, raised the possibility that histones may function in cellular copper homeostasis. We report that the recombinant Xenopus laevis H3-H4 tetramer is an oxidoreductase enzyme that binds Cu2+ and catalyzes its reduction to Cu1+ in vitro. Loss- and gain-of-function mutations of the putative active site residues correspondingly altered copper binding and the enzymatic activity, as well as intracellular Cu1+ abundance and copper-dependent mitochondrial respiration and Sod1 function in the yeast Saccharomyces cerevisiae. The histone H3-H4 tetramer, therefore, has a role other than chromatin compaction or epigenetic regulation and generates biousable Cu1+ ions in eukaryotes.

scholarly journals Identification of putative active site residues of ACAT enzymes

2008 ◽  
Vol 49 (8) ◽  
pp. 1770-1781 ◽  
Author(s):  
Akash Das ◽  
Matthew A. Davis ◽  
Lawrence L. Rudel
Keyword(s):  
Active Site ◽  
Active Site Residues ◽  
Putative Active Site
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