2a8m
From Proteopedia
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Crystal Structure of Human Taspase1 (T234S mutant)
Overview
Taspase1 catalyzes the proteolytic processing of the mixed lineage, leukemia (MLL) nuclear protein, which is required for maintaining Hox gene, expression patterns. Chromosomal translocations of the MLL gene are, associated with leukemia in infants. Taspase1, a threonine aspartase, is a, member of the type 2 asparaginase family, but is the only protease in this, family. We report here the crystal structures of human activated Taspase1, and its proenzyme, as well as the characterization of the effects of, mutations in the active site region using a newly developed fluorogenic, assay. The structure of Taspase1 has significant differences from other, asparaginases, especially near the active site. Mutation of the catalytic, nucleophile, Thr234, abolishes autocatalytic processing in cis but does, not completely block proteolysis in trans. The structure unexpectedly, showed the binding of a chloride ion in the active site, and our kinetic, studies confirm that chlorides ions are inhibitors of this enzyme at, physiologically relevant concentrations.
About this Structure
2A8M is a Single protein structure of sequence from Homo sapiens with CL as ligand. Full crystallographic information is available from OCA.
Reference
Crystal structure of human Taspase1, a crucial protease regulating the function of MLL., Khan JA, Dunn BM, Tong L, Structure. 2005 Oct;13(10):1443-52. PMID:16216576
Page seeded by OCA on Mon Nov 12 20:47:30 2007
Categories: Homo sapiens | Single protein | Dunn, B.M. | Khan, J.A. | Tong, L. | CL | Asparaginase | Leukemia | Mll | Taspase
