2hh7 | pdb_00002hh7
Crystal Structure of Cu(I) bound CsoR from Mycobacterium tuberculosis.
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Overview
Copper is an essential element that becomes highly cytotoxic when, concentrations exceed the capacity of cells to sequester the ion. Here, we, identify a new copper-specific repressor (CsoR) of a copper-sensitive, operon (cso) in Mycobacterium tuberculosis (Mtb) that is representative of, a large, previously uncharacterized family of proteins (DUF156)., Electronic and X-ray absorption spectroscopies reveal that CsoR binds a, single-monomer mole equivalent of Cu(I) to form a trigonally coordinated, (S(2)N) Cu(I) complex. The 2.6-A crystal structure of copper-loaded CsoR, shows a homodimeric antiparallel four-helix bundle architecture that, represents a novel DNA-binding fold. The Cu(I) is coordinated by Cys36, Cys65' and His61' in a subunit bridging site. Cu(I) binding negatively, regulates the binding of CsoR to a DNA fragment encompassing the, operator-promoter region of the Mtb cso operon; this results in, derepression of the operon in Mtb and the heterologous host Mycobacterium, smegmatis. Substitution of Cys36 or His61 with alanine abolishes Cu(I)-, and CsoR-dependent regulation in vivo and in vitro. Potential roles of, CsoR in Mtb pathogenesis are discussed.
About this Structure
2HH7 is a Single protein structure of sequence from Mycobacterium tuberculosis with CU1 as ligand. Full crystallographic information is available from OCA.
Reference
CsoR is a novel Mycobacterium tuberculosis copper-sensing transcriptional regulator., Liu T, Ramesh A, Ma Z, Ward SK, Zhang L, George GN, Talaat AM, Sacchettini JC, Giedroc DP, Nat Chem Biol. 2007 Jan;3(1):60-8. Epub 2006 Dec 3. PMID:17143269
Page seeded by OCA on Wed Nov 21 11:46:09 2007
