1nat
From Proteopedia
CRYSTAL STRUCTURE OF SPOOF FROM BACILLUS SUBTILIS
Overview
Spo0F is a secondary messenger in the "two-component" system controlling the sporulation of Bacillus subtilis. Spo0F, like the chemotaxis protein CheY, is a single-domain protein homologous to the N-terminal activator domain of the response regulators. We recently reported the crystal structure of a phosphatase-resistant mutant Y13S of Spo0F with Ca2+ bound in the active site. The crystal structure of wild-type Spo0F in the absence of a metal ion is presented here. A comparison of the two structures reveals that the cation induces significant changes in the active site. In the present wild-type structure, the carboxylate of Asp11 points away from the center of the active site, whereas when coordinated to the Ca2+, as in the earlier structure, it points toward the active site. In addition, Asp54, the site of phosphorylation, is blocked by a salt bridge interaction of an Arg side chain from a neighboring molecule. From fluorescence quenching studies with Spo0F Y13W, we found that only the amino acid Arg binds to Spo0F in a saturable manner (Kd = 15 mM). This observation suggests that a small molecule with a shape complementary to the active site and having a guanidinium group might inhibit phosphotransfer between response regulators and their cognate histidine kinases.
About this Structure
1NAT is a Single protein structure of sequence from Bacillus subtilis. Full crystallographic information is available from OCA.
Reference
A response regulatory protein with the site of phosphorylation blocked by an arginine interaction: crystal structure of Spo0F from Bacillus subtilis., Madhusudan M, Zapf J, Hoch JA, Whiteley JM, Xuong NH, Varughese KI, Biochemistry. 1997 Oct 21;36(42):12739-45. PMID:9335530 Page seeded by OCA on Sat May 3 02:18:20 2008
