PDBsum entry 3tb7

Hydrolase

PDB id: 3tb7

Contents

Protein chain

188 a.a.

Waters ×30

PDB id:

3tb7

Name:

Hydrolase

Title:

The type i crystal structure of streptococcus agalactiae sortase c1

Structure:

Sortase family protein. Chain: a. Fragment: unp residues 43-260. Synonym: sortase c1, pilus-specific sortase. Engineered: yes

Source:

Streptococcus agalactiae serogroup v. Organism_taxid: 216466. Strain: sag 2603v/r. Gene: sag0647. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

2.45Å R-factor: 0.232 R-free: 0.308

Authors:

B.Khare

Key ref:

B.Khare et al. (2011). The crystal structure analysis of group B Streptococcus sortase C1: a model for the "lid" movement upon substrate binding. J Mol Biol, 414, 563-577. PubMed id: 22033482

Date:

05-Aug-11 Release date: 26-Oct-11

Protein chain

Q8E0S7  (Q8E0S7_STRA5) -  Sortase family protein from Streptococcus agalactiae serotype V (strain ATCC BAA-611 / 2603 V/R)

Seq: 305 a.a.

Struc: 188 a.a.

Enzyme reactions

• Enzyme class: E.C.3.4.22.- - ?????

J Mol Biol 414:563-577 (2011)

PubMed id: 22033482

The crystal structure analysis of group B Streptococcus sortase C1: a model for the "lid" movement upon substrate binding.

B.Khare, Z.Q.Fu, I.H.Huang, H.Ton-That, S.V.Narayana.

ABSTRACT

A unique feature of the class-C-type sortases, enzymes essential for Gram-positive pilus biogenesis, is the presence of a flexible "lid" anchored in the active site. However, the mechanistic details of the "lid" displacement, suggested to be a critical prelude for enzyme catalysis, are not yet known. This is partly due to the absence of enzyme-substrate and enzyme-inhibitor complex crystal structures. We have recently described the crystal structures of the Streptococcus agalactiae SAG2603 V/R sortase SrtC1 in two space groups (type II and type III) and that of its "lid" mutant and proposed a role of the "lid" as a protector of the active-site hydrophobic environment. Here, we report the crystal structures of SAG2603 V/R sortase C1 in a different space group (type I) and that of its complex with a small-molecule cysteine protease inhibitor. We observe that the catalytic Cys residue is covalently linked to the small-molecule inhibitor without lid displacement. However, the type I structure provides a view of the sortase SrtC1 lid displacement while having structural elements similar to a substrate sorting motif suitably positioned in the active site. We propose that these major conformational changes seen in the presence of a substrate mimic in the active site may represent universal features of class C sortase substrate recognition and enzyme activation.