PDBsum entry 4ehc

Hydrolase

PDB id

4ehc

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Contents

			Protein chain

					280 a.a.

			Ligands

					EDO ×31

			Metals

					_ZN

			Waters ×209

PDB id:

4ehc

Links

Name:

Hydrolase

Title:

Crystal structure of thE C-terminal domain of rv0977 of mycobacterium tuberculosis

Structure:

Pe-pgrs family protein. Chain: a. Fragment: aspartic proteinase, unp residues 651-923. Engineered: yes

Source:

Mycobacterium tuberculosis. Organism_taxid: 1773. Strain: h37rv. Gene: pe_pgrs16, rv0977. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

1.98Å

R-factor:

0.167

R-free:

0.213

Authors:

D.V.Barathy,K.Suguna

Key ref:

D.V.Barathy and K.Suguna (2013). Crystal structure of a putative aspartic proteinase domain of the Mycobacterium tuberculosis cell surface antigen PE_PGRS16. Febs Open Bio, 3, 256-262. PubMed id: 23923105 DOI: 10.1016/j.fob.2013.05.004

Date:

02-Apr-12

Release date:

19-Jun-13

PROCHECK

	Headers

	References

Protein chain

Q79FU3 (PG16_MYCTU) - PE-PGRS family protein PE_PGRS16 from Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv)

Seq: Struc:

Seq: Struc:					923 a.a. 280 a.a.*

Key:

PfamA domain

Secondary structure

CATH domain

* PDB and UniProt seqs differ at 10 residue positions (black crosses)

DOI no: 10.1016/j.fob.2013.05.004	Febs Open Bio 3:256-262 (2013)
PubMed id: 23923105

Crystal structure of a putative aspartic proteinase domain of the Mycobacterium tuberculosis cell surface antigen PE_PGRS16.
D.V.Barathy, K.Suguna.

ABSTRACT

We report the crystal structure of the first prokaryotic aspartic proteinase-like domain identified in the genome of Mycobacterium tuberculosis. A search in the genomes of Mycobacterium species showed that the C-terminal domains of some of the PE family proteins contain two classic DT/SG motifs of aspartic proteinases with a low overall sequence similarity to HIV proteinase. The three-dimensional structure of one of them, Rv0977 (PE_PGRS16) of M. tuberculosis revealed the characteristic pepsin-fold and catalytic site architecture. However, the active site was completely blocked by the N-terminal His-tag. Surprisingly, the enzyme was found to be inactive even after the removal of the N-terminal His-tag. A comparison of the structure with pepsins showed significant differences in the critical substrate binding residues and in the flap tyrosine conformation that could contribute to the lack of proteolytic activity of Rv0977.