Unusual 1-3 peptidoglycan cross-links in Acetobacteraceae are made by L,D-transpeptidases with a catalytic domain distantly related to YkuD domains.
J Biol Chem
; 300(1): 105494, 2024 Jan.
Article
em En
| MEDLINE
| ID: mdl-38006948
ABSTRACT
Peptidoglycan is an essential component of the bacterial cell envelope that contains glycan chains substituted by short peptide stems. Peptide stems are polymerized by D,D-transpeptidases, which make bonds between the amino acid in position four of a donor stem and the third residue of an acceptor stem (4-3 cross-links). Some bacterial peptidoglycans also contain 3-3 cross-links that are formed by another class of enzymes called L,D-transpeptidases which contain a YkuD catalytic domain. In this work, we investigate the formation of unusual bacterial 1-3 peptidoglycan cross-links. We describe a version of the PGFinder software that can identify 1-3 cross-links and report the high-resolution peptidoglycan structure of Gluconobacter oxydans (a model organism within the Acetobacteraceae family). We reveal that G. oxydans peptidoglycan contains peptide stems made of a single alanine as well as several dipeptide stems with unusual amino acids at their C-terminus. Using a bioinformatics approach, we identified a G. oxydans mutant from a transposon library with a drastic reduction in 1-3 cross-links. Through complementation experiments in G. oxydans and recombinant protein production in a heterologous host, we identify an L,D-transpeptidase enzyme with a domain distantly related to the YkuD domain responsible for these non-canonical reactions. This work revisits the enzymatic capabilities of L,D-transpeptidases, a versatile family of enzymes that play a key role in bacterial peptidoglycan remodelling.
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MEDLINE
Assunto principal:
Proteínas de Bactérias
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Peptidoglicano
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Modelos Moleculares
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Peptidil Transferases
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Gluconobacter oxydans
Idioma:
En
Ano de publicação:
2024
Tipo de documento:
Article