A Response Regulatory Protein with the Site of Phosphorylation Blocked by an Arginine Interaction: Crystal Structure of Spo0F from Bacillus subtilis
| Autor: | Kottayil I. Varughese, Nguyen-Huu Xuong, Madhusudan M, James A. Hoch, J Zapf, J. M. Whiteley |
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| Rok vydání: | 1997 |
| Předmět: |
Models
Molecular Arginine Protein Conformation Stereochemistry Molecular Sequence Data Static Electricity Mutant Bacillus subtilis Crystallography X-Ray Second Messenger Systems Biochemistry Protein Structure Secondary chemistry.chemical_compound Bacterial Proteins Carboxylate Phosphorylation chemistry.chemical_classification Binding Sites biology Activator (genetics) fungi Active site biology.organism_classification Recombinant Proteins Amino acid Kinetics Amino Acid Substitution chemistry Mutagenesis Site-Directed biology.protein Calcium |
| Zdroj: | Biochemistry. 36:12739-12745 |
| ISSN: | 1520-4995 0006-2960 |
| DOI: | 10.1021/bi971276v |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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