Taxonomic distribution of proteins containing PASTA domains

The tree below includes only several representative species and genera. The complete taxonomic breakdown of all proteins containing PASTA domains can be accessed here. Click the counts or percentage values to display the corresponding proteins.

The PASTA domain: a beta-lactam-binding domain.

Yeats C, Finn R, Bateman A
Trends Biochem Sci. 2002; 27: 438-438

The PASTA domain (for penicillin-binding protein and serine/threonine kinase associated domain) is found in the high molecular weight penicillin-binding proteins and eukaryotic-like serine/threonine kinases of a range of pathogens. We describe this previously uncharacterized domain and infer that it binds beta-lactam antibiotics and their peptidoglycan analogues. We postulate that PknB-like kinases are key regulators of cell-wall biosynthesis. The essential function of these enzymes suggests an additional pathway for the action of beta-lactam antibiotics.

Crystal structure of a deacylation-defective mutant of penicillin-bindingprotein 5 at 2.3-A resolution.

Davies C, White SW, Nicholas RA
J Biol Chem. 2001; 276: 616-23

Penicillin-binding protein 5 (PBP 5) of Escherichia coli functions as ad-alanine carboxypeptidase, cleaving the C-terminal d-alanine residue fromcell wall peptides. Like all PBPs, PBP 5 forms a covalent acyl-enzymecomplex with beta-lactam antibiotics; however, PBP 5 is distinguished byits high rate of deacylation of the acyl-enzyme complex (t(12)approximately 9 min). A Gly-105 --> Asp mutation in PBP 5 markedly impairsthis beta-lactamase activity (deacylation), with only minor effects onacylation, and promotes accumulation of a covalent complex with peptidesubstrates. To gain further insight into the catalytic mechanism of PBP 5,we determined the three-dimensional structure of the G105D mutant form ofsoluble PBP 5 (termed sPBP 5') at 2.3 A resolution. The structure iscomposed of two domains, a penicillin binding domain with a strikingsimilarity to Class A beta-lactamases (TEM-1-like) and a domain of unknownfunction. In addition, the penicillin-binding domain contains an activesite loop spatially equivalent to the Omega loop of beta-lactamases. Inbeta-lactamases, the Omega loop contains two amino acids involved incatalyzing deacylation. This similarity may explain the highbeta-lactamase activity of wild-type PBP 5. Because of the low rate ofdeacylation of the G105D mutant, visualization of peptide substrates boundto the active site may be possible.