Disease relevance of nusA

• The nucleotide sequence of the cloned nusA gene and its flanking region of Escherichia coli [1].
• The nusA gene protein of Escherichia coli and N gene protein of bacteriophage lambda interact in vitro and cooperate in vivo to prevent transcription termination [2].
• This homology is not shared by the N-terminal domain of ntrC, which is clearly but unexpectedly related to the N-terminal domains of a diverse set of procaryotic pleiotropic control proteins, including ompR, dye and nusA from Escherichia coli and spoOA and spoOF from Bacillus subtilis [3].
• Isolation of a recombinant lambda phage carrying nusA and surrounding region of the Escherichia coli K-12 chromosome [4].
• In this situation, the nusA gene of Salmonella, substituted into the Escherichia coli host, prevents lacZ function, confirming that a good facsimile of lambda's specific antitermination mechanism has been recreated [5].

High impact information on nusA

• The DNA sequence at tL shows striking homologies with trp t', a terminator also strongly affected in vitro by the nusA protein [6].
• We have determined the effects of the nusA gene protein and the regulatory nucleotide guanosine tetraphosphate (ppGpp) on pausing and termination of transcription in the leader region of the rrnB operon in vitro [6].
• A completed termination event at tR2 requires both the nusA gene protein and the previously described E. coli termination factor rho [2].
• In vitro the nusA gene protein causes RNA polymerase to pause in the tR2 terminator region of lambda DNA [2].
• In vivo evidence that the nusA and infB genes of E. coli are part of the same multi-gene operon which encodes at least four proteins [7].

Chemical compound and disease context of nusA

• Genetic interaction between the beta' subunit of RNA polymerase and the arginine-rich domain of Escherichia coli nusA protein [8].
• From either template, synthesis of the NH2-terminal dipeptide of sigma, fMet-Glu, is stimulated about threefold by the E. coli nusA gene product [9].
• Synthesis of trp mRNA in vitro directed by plasmid DNA carrying the entire trp operon was studied using crude protein extracts (S-100) from Escherichia coli strains carrying the nusA or nusB mutation or both [10].

Biological context of nusA

• The nusA gene is immediately followed by another open reading frame encoding a polypeptide of at least 22 amino acids, which was identified as the initial portion of the infB structural gene [1].
• The genes infB, for translational initiation factor IF2, and nusA for a protein involved in transcription termination are carried on a 4.8 X 10(3) base-pair DNA fragment [11].
• Transcriptional polarity in rRNA operons of Escherichia coli nusA and nusB mutant strains [12].
• We compared the promoter region of the metZ gene with that of the metY gene, which encodes the tRNA(f2Met) and is located in the promoter-proximal portion of the nusA operon [13].
• However it has not been known whether the expression in E. coli of IF2 beta and IF2 gamma is dependent on or related to a posttranscriptional processing of the polycistronic nusA operon, containing infB, the gene for IF2 [14].

Anatomical context of nusA

• This phenotype, previously seen in rpsL1204 strains whose ribosomes are pseudodependent on streptomycin and work at suboptimal elongation rate, indicates that RNA polymerase escapes from the ribosomes in the pyrE attenuator region in the nusA mutant [15].

Physical interactions of nusA

• The E. coli transcription termination factor rho binds specifically to purified nusA protein [16].

Other interactions of nusA

• Thus, strains carrying either a nusA mutation or a nusB mutation have defects in transcription of 23S rRNA [12].
• A novel plasmid vector, pAMH70 carrying both the lamB and nusA genes of Escherichia coli K12 was constructed [17].
• The P35 gene, which is located in the nusA-infB operon in E. coll, was designated orp (osmoprotectant regulator of PLC) [18].
• Implications of the sequence homologies found among htpR, rpoD, and nusA proteins are discussed [19].
• Enzyme production was not further enhanced by any of the following chromosomal mutations: dnaA, recBC, tob, or nusA snu [20].

Analytical, diagnostic and therapeutic context of nusA

• Sequence analysis of the chromosomal region flanking the Tn5 within KW239 revealed strong similarities to a number of known Escherichia coli gene products and DNA sequences: the nusA operon, including the complete initiator tRNA(Met) gene, metY; a tRNA(Leu) gene; the tpiA gene product; and the MrsA protein [21].

References