Disease relevance of nusB

• The nusB (groNB) gene product of Escherichia coli plays a pivotal role in allowing bacteriophage lambda N protein to function as an antiterminator of mRNA transcription and in modulating host gene expression [1].
• Transcriptional polarity in rRNA operons of Escherichia coli nusA and nusB mutant strains [2].

High impact information on nusB

• This factor does not act by processing a preformed RNA transcript, nor is it replaced by rho protein or nusA or nusB proteins [3].
• Here we present the primary DNA sequence of the nusB gene [1].
• The nusB gene of E. coli has been cloned in plasmid pBR322 [4].
• The possibility that the nusB gene consists of an operon is discussed [4].
• After the coding region, there is a G-C rich inverted repeat sequence followed by a run of Ts, which could be a transcriptional terminator of the nusB gene [4].

Biological context of nusB

• The coding region consists of 417 base pairs (bp), which specify a protein of 139 amino acids, and the calculated molecular weight of the nusB protein is 15,702 [4].
• The ssyB63 (Cs) mutation is an insertion mutation in nusB, while the nusB5 (Cs) mutation suppresses secY24, indicating that inactivation of nusB causes cold-sensitive cell growth as well as phenotypic suppression of secY24 [5].
• The secD gene is closely linked to tsx on the E. coli chromosome, but separable from another gene proposed to be involved in export, ssaD, which maps nearby [6].
• Most groNB mutations isolated at 42 degrees C were found to interfere in addition with bacterial growth at low temperatures, since (a) the GroNB phenotypes of lambda growth inhibition and bacterial cold sensitivity cannot be separated by P1 transduction, and (b) some cold resistant revertants simultaneously become Gro+ for lambda growth [7].
• Lambda transducing phages carrying the groNB+ bacterial gene have been isolated [7].

Other interactions of nusB

• Thus, strains carrying either a nusA mutation or a nusB mutation have defects in transcription of 23S rRNA [2].
• Studies identifying the amino acid changes caused by mutations in nusB and nusE and relating these changes to altered function are reported [8].

Analytical, diagnostic and therapeutic context of nusB

• Molecular cloning and nucleotide sequencing of the nusB gene of E. coli [4].

References