PDBsum entry 4iec

Hydrolase

PDB id: 4iec

Contents

Protein chain

282 a.a.

Metals

__K

_CO ×2

Waters ×191

PDB id:

4iec

Name:

Hydrolase

Title:

Cys105 covalent modification by 2-hydroxyethyl disulfide in mycobacterium tuberculosis methionine aminopeptidase type 1c

Structure:

Methionine aminopeptidase 2. Chain: a. Synonym: map, peptidase m. Engineered: yes

Source:

Mycobacterium tuberculosis. Organism_taxid: 1773. Gene: map. Expressed in: escherichia coli. Expression_system_taxid: 562

Resolution:

2.00Å R-factor: 0.169 R-free: 0.236

Authors:

R.Reddi,R.Gumpena,C.Kishor,A.Addlagatta

Key ref:

R.Reddi et al. (2014). Selective targeting of the conserved active site cysteine of Mycobacterium tuberculosis methionine aminopeptidase with electrophilic reagents. Febs J, 281, 4240-4248. PubMed id: 24841365 DOI: 10.1111/febs.12847

Date:

13-Dec-12 Release date: 18-Dec-13

Protein chain

P9WK19  (MAP12_MYCTU) -  Methionine aminopeptidase 2 from Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv)

Seq: 285 a.a.

Struc: 282 a.a.*

* PDB and UniProt seqs differ at 2 residue positions (black crosses)

Enzyme reactions

• Enzyme class: E.C.3.4.11.18 - methionyl aminopeptidase.
• Reaction: Release of N-terminal amino acids, preferentially methionine, from peptides and arylamides.
• Cofactor: Cobalt cation

DOI no: 10.1111/febs.12847

Febs J 281:4240-4248 (2014)

PubMed id: 24841365

Selective targeting of the conserved active site cysteine of Mycobacterium tuberculosis methionine aminopeptidase with electrophilic reagents.

R.Reddi, T.Arya, C.Kishor, R.Gumpena, R.J.Ganji, S.Bhukya, A.Addlagatta.

ABSTRACT

Methionine aminopeptidases (MetAPs) cleave initiator methionine from ~ 70% of the newly synthesized proteins in every living cell, and specific inhibition or knockdown of this function is detrimental. MetAPs are metalloenzymes, and are broadly classified into two subtypes, type I and type II. Bacteria contain only type I MetAPs, and the active site of these enzymes contains a conserved cysteine. By contrast, in type II enzymes the analogous position is occupied by a conserved glycine. Here, we report the reactivity of the active site cysteine in a type I MetAP, MetAP1c, of Mycobacterium tuberculosis (MtMetAP1c) towards highly selective cysteine-specific reagents. The authenticity of selective modification of Cys105 of MtMetAP1c was established by using site-directed mutagenesis and crystal structure determination of covalent and noncovalent complexes. On the basis of these observations, we propose that metal ions in the active site assist in the covalent modification of Cys105 by orienting the reagents appropriately for a successful reaction. These studies establish, for the first time, that the conserved cysteine of type I MetAPs can be targeted for selective inhibition, and we believe that this chemistry can be exploited for further drug discovery efforts regarding microbial MetAPs.