Alterations in the β flap and β' dock domains of the RNA polymerase abolish NusA-mediated feedback regulation of the metY-nusA-infB operon

Bylund, Göran OUmeå universitet,Institutionen för medicinsk kemi och biofysik (författare)

The RimM protein in Escherichia coli is important for the in vivo maturation of 30S ribosomal subunits and a ΔrimM mutant grows poorly due to assembly and translational defects. These deficiencies are suppressed partially by mutations that increase the synthesis of another assembly protein, RbfA, encoded by the metY-nusA-infB operon. Among these suppressors are mutations in nusA that impair the NusA-mediated negative-feedback regulation at internal intrinsic transcriptional terminators of the metY-nusA-infB operon. We describe here the isolation of two new mutations, one in rpoB and one in rpoC (encoding the β and β' subunits of the RNA polymerase, respectively), that increase the synthesis of RbfA by preventing NusA from stimulating termination at the internal intrinsic transcriptional terminators of the metY-nusA-infB operon. The rpoB2063 mutation changed the isoleucine in position 905 of the β flap-tip helix to a serine, while the rpoC2064 mutation duplicated positions 415 to 416 (valine-isoleucine) at the base of the β' dock domain. These findings support previously published in vitro results, which have suggested that the β flap-tip helix and β' dock domain at either side of the RNA exit tunnel mediate the binding to NusA during transcriptional pausing and termination.

MEDICIN OCH HÄLSOVETENSKAP Medicinska och farmaceutiska grundvetenskaper Mikrobiologi inom det medicinska området hsv//swe
MEDICAL AND HEALTH SCIENCES Basic Medicine Microbiology in the medical area hsv//eng
ribosome maturation protein; escherichia-coli operon; termination factor-rho; messenger-rna; polynucleotide phosphorylase; transcription elongation; nucleotide-sequence; level expression; gene; rimm

Nord, StefanUmeå universitet,Virologi(Swepub:umu)list3101 (författare)
Lövgren, J Mattias (författare)
Wikström, P MikaelUmeå universitet,Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet)(Swepub:umu)miwi0005 (författare)
Umeå universitetInstitutionen för medicinsk kemi och biofysik (creator_code:org_t)

Av författaren/redakt...: Bylund, Göran O; Nord, Stefan; Lövgren, J Matti ...; Wikström, P Mika ...

Om ämnet

MEDICIN OCH HÄLSOVETENSKAP: MEDICIN OCH HÄLS ...; och Medicinska och f ...; och Mikrobiologi ino ...

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.