Alanine racemase (Alr) is a pyridoxal-5'-phosphate-dependent (PLP) enzyme that catalyzes a reversible racemization between the enantiomers of alanine. d-Alanine is an indispensable constituent in the biosynthesis of bacterial cell-wall peptidoglycan, and its inhibition is lethal to prokaryotes, which makes it an attractive target for designing antibacterial drugs. In this study, the molecular structure of alanine racemase from Bacillus pseudofirmus OF4 (DadX) was determined by X-ray crystallography to a resolution of 1.8 Å. The comparison of DadX with alanine racemases from other bacteria demonstrated a conserved overall fold. Enzyme kinetics analysis showed that the conserved residues at the substrate entryway and the salt bridge at the dimer interface are critical for enzyme activity. These structural and biochemical findings provide a template for future structure-based drug-development efforts targeting alanine racemases.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.bbrc.2018.02.041 | DOI Listing |
J Mol Evol
January 2025
Department of Plant and Soil Sciences, 311 Plant Science Building, University of Kentucky, Lexington, KY, 40546-0312, USA.
Amino acid racemases catalyze the interconversion of L- and D-amino acids, maintaining intracellular levels of both D- and L-amino acids. While alanine and glutamate racemases are widespread in bacteria, serine racemase (SerR) is predominantly found in animals. Recently, homologs of animal SerR were reported in some bacterial genomes, but their evolutionary distribution and functional roles remain poorly understood.
View Article and Find Full Text PDFSci Rep
December 2024
Department of Life Sciences, Pohang University of Science and Technology, Pohang, 37673, Kyungbook, Republic of Korea.
Alanine racemase (Alr) catalyzes the pyridoxal 5'-phosphate (PLP)-dependent racemization between L- and D-alanine in bacteria. Owing to the potential interest in targeting Alr for antibacterial drug development, several studies have determined the structures of Alr from different species, proposing models for the reaction mechanism. Insights into its reaction dynamics may be conducive to a better understanding of the Alr reaction mechanism.
View Article and Find Full Text PDFJ Biol Chem
November 2024
Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada. Electronic address:
Fusobacterium nucleatum is an oral commensal bacterium that can act as an opportunistic pathogen and is implicated in diseases such as periodontitis, adverse pregnancy outcomes, colorectal cancer, and Alzheimer's disease. F. nucleatum synthesizes lanthionine for its peptidoglycan, rather than meso-2,6-diaminopimelic acid (DAP) used by most Gram-negative bacteria.
View Article and Find Full Text PDFAppl Environ Microbiol
October 2024
Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, USA.
The symbiosis between and the Hawaiian bobtail squid, , is a tractable and well-studied model of bacteria-animal mutualism. Here, we developed a method to transiently colonize using D-alanine (D-ala) auxotrophy of the symbiont, controlling the persistence of viable infection by supplying or withholding D-ala. We generated alanine racemase () mutants of that lack avenues for mutational suppression of auxotrophy or reversion to prototrophy.
View Article and Find Full Text PDFMethods Mol Biol
August 2024
Department of Food Management, Miyagi University, Sendai, Japan.
The D-amino acids of D-alanine, D-glutamic acid, and D-aspartic acid increase tasting evaluation scores of Sake, a Japanese traditional alcohol beverage. Sake is brewed using seed mash for growth of brewing yeast without growth of contaminating microorganisms. Kimoto is brewed using lactic acid bacteria growth to decrease pH.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!