Bacterial wall peptidoglycan, DD-peptidases and beta-lactam antibiotics.
Wall peptidoglycan expansion in bacteria rests upon a cytoplasmic D-Ala: D-Ala ligase (ADP) which catalyses synthesis of a D-Ala-D-Ala dipeptide (with accompanying hydrolysis of one molecule of ATP) and a set of DD-peptidases which utilize this D-Ala-D-Ala dipeptide--once it has been translocated at the outer face of the plasma membrane as the C-terminal portion of a disaccharide peptide unit--as carbonyl donor for transpeptidation and carboxypeptidation reactions (without additional energy expenditure). Four DD-peptidases have been selected which differ from each other with respect to the effects that amino compounds exert on the fate and rate of consumption of a D-Ala-D-Ala terminated amide carbonyl donor analogue. They serve as models to understand the different mechanisms by which the DD-peptidases perform catalysis and show widely varying responses to the action of beta-lactams, from extreme sensitivity to very high resistance.
D000604:Amino Acyl-tRNA Synthetases / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects* / Q000378:metabolism; D002473:Cell Wall / Q000378:metabolism*; D002918:Chymotrypsin / Q000378:metabolism; D004150:Dipeptidases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008954:Models, Biological; D010457:Peptidoglycan / Q000378:metabolism*; D010458:Peptidyl Transferases / Q000378:metabolism; D013329:Structure-Activity Relationship; D047090:beta-Lactams
D000900:Anti-Bacterial Agents; D010457:Peptidoglycan; D047090:beta-Lactams; D010458:Peptidyl Transferases; D004150:Dipeptidases; D002918:Chymotrypsin; D000604:Amino Acyl-tRNA Synthetases