Biomedical subjects

M Yudkin

Publications and source records attributed to M Yudkin.

4 recordsLinked to original sources

PubMed2001

NMR studies of the sporulation protein SpoIIAA: implications for the regulation of the transcription factor sigmaF in Bacillus subtilis.

SpoIIAA participates in a four-component mechanism for phosphorylation-dependent transcription control at the outset of sporulation. We report the refinement of the solution structure of SpoIIAA by using the automated iterative NOE assignment method ARIA. To complement the structural data, the protein dynamics were determined by measuring the T1, T2 and NOE of the backbone 15N-nuclei. The refined structure permits a discussion of the structural features that are important for the function of SpoIIAA in the regulation of the sporulation sigma factor sigmaF, and for homologous regulatory pathways present in B. subtilis and in other bacilli.

Bacillus subtilis↗

PubMed1999

The Bacillus subtilis regulator protein SpoIIE shares functional and structural similarities with eukaryotic protein phosphatases 2C.

Dephosphorylation of SpoIIAA-P by SpoIIE is strictly dependent on the presence of the bivalent metal ions Mn2+ or Mg2+. Replacement by Ala of one of the four Asp residues, invariant in all representatives of protein phosphatase 2C, completely abolished the SpoIIE phosphatase activity in vitro, whilst replacement of the Asp residues by another acidic amino acid, Glu, had varying effects on the activities of the resulting mutated proteins. D610E and D795E exhibited some residual activity while D628E and D745E were without enzymatic activity. The results suggest that the functional model in which metal-associated water molecules are involved in the dephosphorylation reaction catalyzed by human protein phosphatase 2C alpha can also be applied to the bacterial protein phosphatase 2C-like protein.

Amino Acid Sequence↗

PubMed1983

The pattern of protein synthesis in spoIVC mutants of Bacillus subtilis resuspended in sporulation medium.

Two spoIVC mutants of Bacillus subtilis were labelled with [35S]methionine either at the time of resuspension in sporulation medium or 1, 2 or 3 h later, and radioactive proteins were detected after cell extracts had been subjected to two-dimensional gel electrophoresis. The mutants completed almost all of the changes in protein synthesis that occur in the wild-type in these conditions. A heavily labelled protein was found in the mutants that has also been observed in a spoO mutant but does not occur in the wild-type.

Bacillus subtilis↗

PubMedDate not supplied

Spore formation in Bacillus subtilis.

Bacillus subtilis is the best studied of the bacteria that make heat-resistant spores in response to starvation. The process of sporulation results in the formation of a cell type which is quite different in morphology from that of bacteria during normal growth. Sporulation requires the activation, in an ordered sequence, of many genes that are kept silent during vegetative growth. It also requires that these genes be activated differentially in two sister cells that are genetically identical. The sophisticated mechanisms responsible for both the temporal and the spatial regulation of gene expression are now understood in a fair amount of detail. They are likely to provide models which will make a valuable contribution to studies of development and differentiation in higher cells.

Bacillus subtilis↗