PDBsum entry 4fh4

Hydrolase

PDB id: 4fh4

Contents

Protein chain

265 a.a.

Ligands

MA4 ×2

Waters ×446

PDB id:

4fh4

Name:

Hydrolase

Title:

High-resolution structure of apo wt shv-1 beta-lactamase

Structure:

Beta-lactamase shv-1. Chain: a. Fragment: unp residues 22-286. Synonym: pit-2. Engineered: yes

Source:

Klebsiella pneumoniae. Organism_taxid: 573. Gene: bla, shv1. Expressed in: escherichia coli. Expression_system_taxid: 562

Resolution:

1.09Å R-factor: 0.136 R-free: 0.166

Authors:

E.A.Rodkey,F.Van Den Akker

Key ref:

E.A.Rodkey et al. (2012). Crystal structure of a preacylation complex of the β-lactamase inhibitor sulbactam bound to a sulfenamide bond-containing thiol-β-lactamase. J Am Chem Soc, 134, 16798-16804. PubMed id: 22974281

Date:

05-Jun-12 Release date: 26-Sep-12

Protein chain

P0AD64  (BLA1_KLEPN) -  Beta-lactamase SHV-1 from Klebsiella pneumoniae

Seq: 286 a.a.

Struc: 265 a.a.

Enzyme reactions

• Enzyme class: E.C.3.5.2.6 - beta-lactamase.
• Pathway: Penicillin Biosynthesis and Metabolism
• Reaction: a beta-lactam + H2O = a substituted beta-amino acid
• Cofactor: Zn(2+)

J Am Chem Soc 134:16798-16804 (2012)

PubMed id: 22974281

Crystal structure of a preacylation complex of the β-lactamase inhibitor sulbactam bound to a sulfenamide bond-containing thiol-β-lactamase.

E.A.Rodkey, S.M.Drawz, J.M.Sampson, C.R.Bethel, R.A.Bonomo, F.van den Akker.

ABSTRACT

The rise of inhibitor-resistant and other β-lactamase variants is generating an interest in developing new β-lactamase inhibitors to complement currently available antibiotics. To gain insight into the chemistry of inhibitor recognition, we determined the crystal structure of the inhibitor preacylation complex of sulbactam, a clinical β-lactamase inhibitor, bound in the active site of the S70C variant of SHV-1 β-lactamase, a resistance enzyme that is normally present in Klebsiella pneumoniae. The S70C mutation was designed to affect the reactivity of that catalytic residue to allow for capture of the preacylation complex. Unexpectedly, the 1.45 Å resolution inhibitor complex structure revealed that residue C70 is involved in a sulfenamide bond with K73. Such a covalent bond is not present in the wild-type SHV-1 or in an apo S70C structure also determined in this study. This bond likely contributed significantly to obtaining the preacylation complex with sulbactam due to further decreased reactivity toward substrates. The intact sulbactam is positioned in the active site such that its carboxyl moiety interacts with R244, S130, and T235 and its carbonyl moiety is situated in the oxyanion hole. To our knowledge, in addition to being the first preacylation inhibitor β-lactamase complex, this is also the first observation of a sulfenamide bond between a cysteine and lysine in an active site. Not only could our results aid, therefore, structure-based inhibitor design efforts in class A β-lactamases, but the sulfenamide-bond forming approach to yield preacylation complexes could also be applied to other classes of β-lactamases and penicillin-binding proteins with the SXXK motif.