1qnl
From Proteopedia
AMIDE RECEPTOR/NEGATIVE REGULATOR OF THE AMIDASE OPERON OF PSEUDOMONAS AERUGINOSA (AMIC) COMPLEXED WITH BUTYRAMIDE
Structural highlights
FunctionAMIC_PSEAE Negatively regulates the expression of the aliphatic amidase operon. AmiC functions by inhibiting the action of AmiR at the protein level. It exhibits protein kinase activity. Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe AmiC protein in Pseudomonas aeruginosa is the negative regulator and ligand receptor for an amide-inducible aliphatic amidase operon. In the wild-type PAC1 strain, amidase expression is induced by acetamide or lactamide, but not by butyramide. A mutant strain of P. aeruginosa, PAC181, was selected for its sensitivity to induction by butyramide. The molecular basis for the butyramide inducible phenotype of P.aeruginosa PAC181 has now been determined, and results from a Thr-->Asn mutation at position 106 in PAC181-AmiC. In the wild-type PAC1-AmiC protein this residue forms part of the side wall of the amide-binding pocket but does not interact with the acetamide ligand directly. In the crystal structure of PAC181-AmiC complexed with butyramide, the Thr-->Asn mutation increases the size of the ligand binding site such that the mutant protein is able to close into its 'on' configuration even in the presence of butyramide. Although the mutation allows butyramide to be recognized as an inducer of amidase expression, the mutation is structurally sub-optimal, and produces a significant decrease in the stability of the mutant protein. Structural adaptation to selective pressure for altered ligand specificity in the Pseudomonas aeruginosa amide receptor, amiC.,O'Hara BP, Wilson SA, Lee AW, Roe SM, Siligardi G, Drew RE, Pearl LH Protein Eng. 2000 Feb;13(2):129-32. PMID:10708652[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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