2FFF

Open Form of a Class A Transpeptidase Domain

Summary for 2FFF

• Entry DOI: 10.2210/pdb2fff/pdb
• Descriptor: penicillin-binding protein 1B, NICKEL (II) ION, ... (4 entities in total)
• Functional Keywords: transpeptidase fold, membrane protein, transferase
• Biological source: Streptococcus pneumoniae; More
• Total number of polymer chains: 2
• Total formula weight: 51500.75

Authors

Lovering, A.L.,Strynadka, N.C.J. (deposition date: 2005-12-19, release date: 2006-06-20, Last modification date: 2023-08-30)

Primary citation

Lovering, A.L.,De Castro, L.,Lim, D.,Strynadka, N.C.
Structural analysis of an "open" form of PBP1B from Streptococcus pneumoniae.
Protein Sci., 15:1701-1709, 2006

PubMed Abstract: The class A PBP1b from Streptococcus pneumoniae is responsible for glycosyltransferase and transpeptidase (TP) reactions, forming the peptidoglycan of the bacterial cell wall. The enzyme has been produced in a stable, soluble form and undergoes time-dependent proteolysis to leave an intact TP domain. Crystals of this TP domain were obtained, diffracting to 2.2 A resolution, and the structure was solved by using molecular replacement. Analysis of the structure revealed an "open" active site, with important conformational differences to the previously determined "closed" apoenzyme. The active-site nucleophile, Ser460, is in an orientation that allows for acylation by beta-lactams. Consistent with the productive conformation of the conserved active-site catalytic residues, adjacent loops show only minor deviation from those of known acyl-enzyme structures. These findings are discussed in the context of enzyme functionality and the possible conformational sampling of PBP1b between active and inactive states.

PubMed: 16751607
DOI: 10.1110/ps.062112106

Experimental method

X-RAY DIFFRACTION (2.23 Å)