Crystal structure of a putative aspartic proteinase domain of the Mycobacterium tuberculosis cell surface antigen PE_PGRS16.

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 critica

SUBMITTER: Barathy DV 

PROVIDER: S-EPMC3722594 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature