Capping protein nucleates the assembly of actin filaments and stabilizes actin filaments by binding to their barbed ends. We describe here a novel isoform of the beta subunit of chicken capping protein, the beta 2 isoform, which arises by alternative splicing. The chicken beta 1 isoform and the beta 2 isoform are identical in their amino acid sequence except for a short region at the COOH termi...

The homodimeric Escherichia coli beta sliding clamp contains two hydrophobic clefts with which proteins involved in DNA replication, repair and damage tolerance interact. Deletion of the C-terminal five residues of beta (beta(C)) disrupted both clefts, severely impairing interactions of the clamp with the DnaX clamp loader, as well as the replicative DNA polymerase, Pol III. In order to determi...

The L-type calcium channel (LTCC) has a variety of physiological roles that are critical for the proper function of many cell types and organs. Recently, a member of the zinc-regulating family of proteins, ZnT-1, was recognized as an endogenous inhibitor of the LTCC, but its mechanism of action has not been elucidated. In the present study, using two-electrode voltage clamp recordings in Xenopu...

We have identified previously a xenobiotic-responsive element, which we termed the beta-naphthoflavone-responsive element, between nucleotide -722 and -682 in the 5'-flanking region of the rat glutathione S-transferase Ya subunit gene (Rushmore, T.H., King, R.G., Paulson, K.E., and Pickett, C.B. (1990) Proc. Natl. Acad. Sci. U.S.A. 87, 3826-3830). The beta-naphthoflavone-responsive element is r...

The Na,K-ATPase alpha isoform (alpha 1, alpha 2, and alpha 3) and beta subunit genes exhibit a complex pattern of expression during heart development. To identify possible molecular signals that regulate the differential expression of these genes, isolated neonatal rat myocardial and non-myocardial cells were cultured in chemically defined medium and the responses of the multiple Na,K-ATPase su...

Lutropin (LH) bears asparagine-linked oligosaccharides terminating with the unique sequence SO4-4GalNAc beta 1-4GlcNAc beta 1-2Man alpha, whereas follitropin (FSH) bears oligosaccharides terminating predominantly with the sequence Sia alpha-Gal beta 1-4GlcNAc beta 1-2Man alpha, where Sia is sialic acid. We previously identified a glycoprotein-hormone-specific N-acetylgalactosamine-transferase (...

The activity of the sigma subunit of the RNA polymerase of Bacillus subtilis decreases markedly during the first 2 hr of sporulation. Moreover, sigma activity remains deficient throughout the sporulation process and in dormant spores. The time course of changes in RNA polymerase during sporulation indicates that alterations in the core of RNA polymerase occur after the loss of sigma activity. C...

The Escherichia coli BglG protein antiterminates transcription at two terminator sites within the bgl operon in response to the presence of beta-glucosides in the growth medium. BglG was previously shown to be an RNA-binding protein that recognizes a specific sequence located just upstream of each of the terminators and partially overlapping with them. We show here that BglG also binds to the E...

The eukaryotic Kv1 voltage-gated K(+) channel is composed of four alpha subunits and four beta subunits. The full-length beta(2) subunit from Rattus norvegicus has been expressed in Esherichia coli, purified and then crystallized. A careful molecular-replacement study using the structure of the truncated beta(2) subunit reveals that the crystals are perfectly pseudo-merohedrally twinned. While ...