JAMES ALFRED HOCH

..New mechanisms of developmental regulation are being uncovered in a variety of microbial systems...

..Elucidation of the structures of the interacting domains is leading to an understanding of the mechanisms of molecular recognition and phosphotransfer in these systems...

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..The KinA and KinB pathways are the only pathways capable of producing sufficient Spo0A approximately P to allow initiation and completion of sporulation under laboratory conditions...

..Our results indicate that lrpA-lrpB together with the biosynthetic glyA gene lie on a common signalling pathway meant to activate the KinB sensor kinase...

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..The results suggest that multiple kinases exist for the Spo0A protein...

..It is apparent that different surfaces of response regulators may be involved in recognition of the protein partners to which they are paired...

..Models for the role of KapB in regulating KinB activity are discussed...

..Such phosphatases are prevalent in signal transduction systems controlling complex processes, such as the initiation of development in microorganisms...

..Implications of these observations on the transcriptional regulation of kinB and the role of KbaA in KinB activation are discussed...

..The N-terminal region appears to be essential both for signal sensing and for maintaining the correct conformation of the autokinase component domains...

..subtilis cells, as determined by beta-galactosidase activity assays from lacZ transcriptional fusion constructions. We found no amino acid sequence homology between the spoIVB gene product and other known bacterial proteins...

..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...

..Since peptide transport is essential for inactivation of the negative regulation of sporulation by Rap phosphatases, the control of ScoC transcription repression activity plays a crucial role in the initiation of sporulation...

..Studies of the regulation of this gene have allowed the generation of a hypothesis to explain the interactions of those five stage 0 genes involved in the activation of sporulation-specific transcription...

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..Information at the molecular level on the interaction between response regulators and phosphohistidine domains is necessary to develop a rationale for how phospho-signaling fidelity is maintained in two-component systems...

..The level of this regulator is, in turn, controlled by the spo0A gene. The pleiotropic phenotypes of spo0A mutants result from uncontrolled overexpression of the abrB regulator...

..The results suggested that stationary phase functions and sporulation are repressed during active growth by AbrB and other transition state regulators by binding to the affected promoters in a concentration-dependent manner...

..We postulate that the accumulation of such peptides may play a signalling role in the initiation of sporulation, and that the sporulation defect in opp mutants results from an inability to transport these peptides...

..The repaired App system can substitute completely for the Opp system in both sporulation and competence for genetic transformation. The phenotypes raised some speculation about the subunit configuration of the Opp system...

..In addition, the current status on the development of inhibitors specific for two-component systems will be discussed...

..The high level of identity of these proteins (71% for YycF) suggests that this system may play a similar role in gram-positive pathogens...

..However, in mixing competition experiments we have shown that Hpr and Sin binding occurred independently, and no visible alterations of protected regions were detected...

..coli ethanolamine ammonia-lyase, except that residue 16 of the large subunit was asparagine in the E. coli sequence and aspartic acid in the S. typhimurium sequence...

..The data suggest that YycH and YycI control the activity of YycG in the periplasm and that this control is crucial in regulating important cellular processes...

..In addition, we discuss how buried residues and intra-protein communication networks contribute to precise molecular recognition by ensuring that the correct surface is presented...

..Most aspects of our approaches are applicable to other two-component systems in B. subtilis and the gram positives. Some are limited to essential systems, such as the YycFG system...

..Structural studies of such domains are leading to an understanding of the mechanisms by which sensor complexes recognize signals and regulate kinase activity...

..The utility of both systems was directly demonstrated through the mutagenesis of a widely used B. anthracis strain...

..An example of such a conversion is seen in Bacillus anthracis, and how acquired plasmid regulatory functions affect the activity of the regulatory processes of the bacterium, and vice versa, is now being revealed...

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..The results indicate that the loss of ResDE-controlled respiratory capacity does not affect the synthesis of anthrax toxin...

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..9-A resolution. YycI forms a dimer, and remarkably the structure resembles that of the two C-terminal domains of YycH despite nearly undetectable sequence homology (10%) between the two proteins...

..Our results link virulence factor production in B. anthracis to carbohydrate metabolism and, for the first time, provide a mechanistic explanation for AtxA transcriptional activity...

..The protein:protein and protein:DNA interfaces revealed in the crystal provide a basis for interpreting the transcription activation process and for the design of drugs to counter infections by these bacteria...

..In Clostridial genomes, only the Spo0A protein was found, suggesting that the anaerobic relatives of the Bacilli do not use a phosphorelay and phosphorylate Spo0A directly with sensor kinases...

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..The sporulation of B. anthracis ex vivo appears to result from any one or a combination of the sporulation sensor histidine kinases remaining...

..Depending on the type of divalent metal ion present, in vitro phosphorylation of Spo0F by its cognate kinase KinA can be inhibited...

..botulinum Spo0A, some of these interactions have been lost...

..3 A data to an R-factor of 25.2%. The molecule is made up of three domains, and has a novel three-dimensional structure. The N-terminal domain features a calcium binding site and the central domain contains two conserved loop regions...

..anthracis sporulation in the bloodstream of its infected host, a salient characteristic in the virulence of this organism, and provides an additional role for the virulence plasmids in anthrax pathogenesis...

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..This review discusses the potential use of two-component systems as targets for antimicrobial therapy against Gram-positive pathogens and the current status in the development of inhibitors specific for these systems...

..NMR dynamics and structural studies of both wild-type and mutant proteins in this cluster suggest that motions serve to precisely arrange the site of phosphoryl transfer within the complex...

..This program has the goal of generating knowledge of the pathogenic regulatory mechanisms employed by toxin producing spore-forming bacteria for which little is known. ..

..The significance of this research is not limited to understanding the phosphorelay and sporulation in a corner of the bacterial world but has regulatory implications for signal transduction in eukaryotes and plants. ..

..This program has the goal of generating knowledge of the pathogenic regulatory mechanisms employed by toxin producing spore-forming bacteria for which little is known. ..

..This is a collaborative effort between investigators with expertise in genetics, biochemistry and structure of Bacillus regulatory proteins. ..

..It is believed that this combination of structural and functional studies will lead to effective anti-bacterial agents either directly or in combination as inhibitors of resistance mechanisms. ..

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..The significance of this research is not limited to understanding the phosphorelay and sporulation in a corner of the bacterial world but has regulatory implications for signal transduction in eukaryotes and plants. ..