1E3A

A slow processing precursor penicillin acylase from Escherichia coli

Summary for 1E3A

• Entry DOI: 10.2210/pdb1e3a/pdb
• Related: 1AI4 1AI5 1AI6 1AI7 1AJN 1AJP 1AJQ 1PNK 1PNL 1PNM
• Descriptor: PENICILLIN AMIDASE ALPHA SUBUNIT, PENICILLIN AMIDASE BETA SUBUNIT, CALCIUM ION, ... (6 entities in total)
• Functional Keywords: antibiotic resistance, amidase, ntn-hydrolase, hydrolysis of penicillin g acylase
• Biological source: ESCHERICHIA COLI; More
• Total number of polymer chains: 2
• Total formula weight: 91910.20

Authors

Hewitt, L.,Kasche, V.,Lummer, K.,Lewis, R.J.,Murshudov, G.N.,Verma, C.S.,Dodson, G.G.,Wilson, K.S. (deposition date: 2000-06-07, release date: 2000-11-29, Last modification date: 2023-12-13)

Primary citation

Hewitt, L.,Kasche, V.,Lummer, K.,Lewis, R.J.,Murshudov, G.N.,Verma, C.S.,Dodson, G.G.,Wilson, K.S.
Structure of a Slow Processing Precursor Penicillin Acylase from Escherichia Coli Reveals the Linker Peptide Blocking the Active-Site Cleft
J.Mol.Biol., 302:887-, 2000

PubMed Abstract: Penicillin G acylase is a periplasmic protein, cytoplasmically expressed as a precursor polypeptide comprising a signal sequence, the A and B chains of the mature enzyme (209 and 557 residues respectively) joined by a spacer peptide of 54 amino acid residues. The wild-type AB heterodimer is produced by proteolytic removal of this spacer in the periplasm. The first step in processing is believed to be autocatalytic hydrolysis of the peptide bond between the C-terminal residue of the spacer and the active-site serine residue at the N terminus of the B chain. We have determined the crystal structure of a slowly processing precursor mutant (Thr263Gly) of penicillin G acylase from Escherichia coli, which reveals that the spacer peptide blocks the entrance to the active-site cleft consistent with an autocatalytic mechanism of maturation. In this mutant precursor there is, however, an unexpected cleavage at a site four residues from the active-site serine residue. Analyses of the stereochemistry of the 260-261 bond seen to be cleaved in this precursor structure and of the 263-264 peptide bond have suggested factors that may govern the autocatalytic mechanism.

PubMed: 10993730
DOI: 10.1006/JMBI.2000.4105

Experimental method

X-RAY DIFFRACTION (1.8 Å)