By a quantitative Western immunoblot analysis, the intracellular levels of two principal sigma subunits, sigma 70 (sigma D, the rpoD gene product) and sigma 38 (sigma S, the rpoS gene product), and of two minor sigma subunits, sigma 54 (sigma N, the rpoN gene product) and sigma 28 (sigma F, the rpoF gene product), were determined in two Escherichia coli strains, W3110 and MC4100. The results in...

Thirteen newly isolated monoclonal antibodies (MAbs) were used to study relationships between reovirus outer capsid proteins sigma 3, mu 1c, and lambda 2 (core spike) and the cell attachment protein sigma 1. We focused on sigma 1-associated properties of serotype specificity and hemagglutination (HA). Competition between MAbs revealed two surface epitopes on mu 1c that were highly conserved bet...

Let $F$ be a non-Archimedean locally compact field‎. ‎Let $sigma$ and $tau$ be finite-dimensional representations of the Weil-Deligne group of $F$‎. ‎We give strong upper and lower bounds for the Artin and Swan exponents of $sigmaotimestau$ in terms of those of $sigma$ and $tau$‎. ‎We give a different lower bound in terms of $sigmaotimeschecksigma$ and $tauotimeschecktau$‎. ‎Using the Langlands...

The specificity of DNA-dependent RNA polymerase for target promotes is largely due to the replaceable sigma subunit that it carries. Multiple sigma proteins, each conferring a unique promoter preference on RNA polymerase, are likely to be present in all bacteria; however, their abundance and diversity have been best characterized in Bacillus subtilis, the bacterium in which multiple sigma facto...