PDBsum entry 5go5

Hydrolase

PDB id: 5go5

Contents

Protein chain

152 a.a.

Ligands

GLY

SO4 ×2

Waters ×154

PDB id:

5go5

Name:

Hydrolase

Title:

Structure of sortase e from streptomyces avermitilis

Structure:

Sortase. Chain: a. Fragment: unp residues 51-230. Synonym: sortase e. Engineered: yes

Source:

Streptomyces avermitilis (strain atcc 31267 / dsm 46492 / jcm 5070 / nbrc 14893 / ncimb 12804 / nrrl 8165 / ma- 4680). Organism_taxid: 227882. Strain: atcc 31267 / dsm 46492 / jcm 5070 / nbrc 14893 / ncimb 12804 / nrrl 8165 / ma-4680. Atcc: atcc 31267d5. Gene: saverm_4333. Expressed in: escherichia coli.

Resolution:

1.65Å R-factor: 0.163 R-free: 0.191

Authors:

S.Das,V.S.Pawale,V.Dadireddy,R.P.Roy,S.Ramakumar

Key ref:

S.Das et al. (2017). Structure and specificity of a new class of Ca²⁺-independent housekeeping sortase fromStreptomyces avermitilisprovide insights into its non-canonical substrate preference. J Biol Chem, 292, 7244-7257. PubMed id: 28270507

Date:

26-Jul-16 Release date: 15-Mar-17

Protein chain

Q82FC3  (Q82FC3_STRAW) -  Secreted protein from Streptomyces avermitilis (strain ATCC 31267 / DSM 46492 / JCM 5070 / NBRC 14893 / NCIMB 12804 / NRRL 8165 / MA-4680)

Seq: 230 a.a.

Struc: 152 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

J Biol Chem 292:7244-7257 (2017)

PubMed id: 28270507

Structure and specificity of a new class of Ca²⁺-independent housekeeping sortase fromStreptomyces avermitilisprovide insights into its non-canonical substrate preference.

S.Das, V.S.Pawale, V.Dadireddy, A.K.Singh, S.Ramakumar, R.P.Roy.

ABSTRACT

Surface proteins in Gram-positive bacteria are incorporated into the cell wall through a peptide ligation reaction catalyzed by transpeptidase sortase. Six main classes (A-F) of sortase have been identified of which class A sortase is meant for housekeeping functions. The prototypic housekeeping sortase A (SaSrtA) fromStaphylococcus aureuscleaves LPXTG-containing proteins at the scissile T-G peptide bond and ligates protein-LPXT to the terminal Gly residue of the nascent cross-bridge of peptidoglycan lipid II precursor. Sortase-mediated ligation ("sortagging") of LPXTG-containing substrates and Gly-terminated nucleophiles occursin vitroas well asin celluloin the presence of Ca²⁺and has been applied extensively for protein conjugations. Although the majority of applications emanate from SaSrtA, low catalytic efficiency, LPXTG specificity restriction, and Ca²⁺requirement (particularly forin celluloapplications) remain a drawback. Given that Gram-positive bacteria genomes encode a variety of sortases, natural sortase mining can be a viable complementary approach akin to engineering of wild-type SaSrtA. Here, we describe the structure and specificity of a new class E sortase (SavSrtE) annotated to perform housekeeping roles inStreptomyces avermitilisBiochemical experiments define the attributes of an optimum peptide substrate, demonstrate Ca²⁺-independent activity, and provide insights about contrasting functional characteristics of SavSrtE and SaSrtA. Crystal structure, substrate docking, and mutagenesis experiments have identified a critical residue that dictates the preference for a non-canonical LAXTG recognition motif over LPXTG. These results have implications for rational tailoring of substrate tolerance in sortases. Besides, Ca²⁺-independent orthogonal specificity of SavSrtE is likely to expand the sortagging toolkit.