The important plant hormone salicylic acid (SA; 2-hydroxybenzoic acid) regulates several key plant responses including, most notably, defence against pathogens. A key enzyme for SA biosynthesis is isochorismate synthase (ICS), which converts chorismate into isochorismate, and for which there are two genes in Arabidopsis thaliana One (AtICS1) has been shown to be required for increased SA biosyn...

Many recombinant proteins are produced as a fusion protein tagging hexahistidine, which has been used for studying their biological function both in vitro and in vivo. Unexpectedly, we observed activation of BALB/c mouse splenocytes when treated with hexahistidine-tagged recombinant proteins. This activation was hexahistidine-specific since the anti-pentahistidine antibody completely neutralize...

Fyn-related kinase (Frk) was first identified using human breast cancer cells. It shares 51% identity with c-Src. Like all members of the Src family, Frk is thought to cause several cancers via dysregulations in signal transduction from cell-surface receptors. The excess activity of Frk on beta-cells has a crucial role in type-I diabetes. A silent mutation at Ile229 conferred a bacterial expres...

The movement proteins of two tobamoviruses (tobacco mosaic virus, TMV, common strain U1 and cruciferous TMV strain) containing amino-terminal hexahistidine affinity tags were overexpressed in Escherichia coli and purified by metal chelate affinity chromatography. Purified recombinant proteins were immobilized to a Ni(2+)-chelate adsorbent and their ability to interact with full-length genomic T...

Salmonella thin aggregative fimbriae (Tafi; curli) are important in pathogenesis and biofilm formation; however, less is known of their structure and morphogenesis. In the Salmonella agfBAC Tafi operon, the transcription and role of agfC have been elusive. In this study, agfBAC transcripts were detected using a sensitive reverse transcriptase technique. Native AgfC was not detected using polycl...

In the mitochondrial ATP synthase (mtATPase) of the yeast Saccharomyces cerevisiae, the stoichiometry of subunits d, oligomycin-sensitivity conferring protein (OSCP), and b is poorly defined. We have investigated the stoichiometry of these subunits by the application of hexahistidine affinity purification technology. We have previously demonstrated that intact mtATPase complexes incorporating a...

Herpes simplex virus 1 (HSV-1) ICP27 and ICP8 proteins have both been implicated in the transcription of late genes and regulation of viral gene expression. We showed previously that ICP27 and ICP8 associate with the RNAP II holoenzyme (Zhou and Knipe, J. Virol. 76, 5893-5904). Here, we demonstrate that ICP27 and ICP8 coprecipitate from lysates of HSV-1-infected HEp2 cells and from lysates of i...

BACKGROUND The detection of unknown mutations is important in research and medicine. For this purpose, a mismatch-specific endonuclease CEL I from celery has been established as a useful tool in high throughput projects. Previously, CEL I-like activities were described only in a variety of plants and could not be expressed in an active form in bacteria. RESULTS We describe expression of activ...

Precursor protein translocation across the Escherichia coli inner membrane is mediated by the translocase, which is composed of a heterotrimeric integral membrane protein complex with SecY, SecE, and SecG as subunits and peripherally bound SecA. Cross-linking experiments were conducted to study which proteins are associated with SecA in vivo. Formaldehyde treatment of intact cells results in th...