title: Identification of a structural element that is essential for two functions of transcription factor NusG.
abstract: The transcription factor NusG from Escherichia coli modulates the rate of transcript elongation by RNA polymerase and the efficiency of Rho-dependent transcript termination. It consists of two globular domains with an extra loop extending out of the amino-terminal domain in the position that is occupied by a third globular domain in some NusG homologues. We have tested the role of this appended mini-domain by assaying the elongation and termination enhancement activities of variants. The results show that variants with changes in their sequence do not cause a loss of functions, whereas variants with the deletions of the residues in that domain are much less active for both functions. This finding suggests that the mini-domain serves as a structural element for an interaction rather than as a site for residue-specific contacts.
authors.affiliation: Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, IN 47405, USA.
authors.forename: Lislott V
authors.initials: LV
authors.lastname: Richardson
authors.forename: John P
authors.initials: JP
authors.lastname: Richardson
mesh_terms: D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics* / Q000502:physiology; D017353:Gene Deletion; D010445:Peptide Elongation Factors / Q000737:chemistry* / Q000235:genetics* / Q000502:physiology; D017434:Protein Structure, Tertiary; D012329:RNA, Bacterial / Q000378:metabolism; D012234:Rho Factor / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics* / Q000502:physiology; D014158:Transcription, Genetic; D035602:Transcriptional Elongation Factors / Q000502:physiology
chemical_list: D029968:Escherichia coli Proteins; C070291:NusG protein, E coli; D010445:Peptide Elongation Factors; D012329:RNA, Bacterial; D012234:Rho Factor; D014157:Transcription Factors; D035602:Transcriptional Elongation Factors; D012321:DNA-Directed RNA Polymerases