Disease relevance of rpsA

• The cmk gene encoding cytidine monophosphate kinase is located in the rpsA operon and is required for normal replication rate in Escherichia coli [1].
• These in vivo results, as well as data obtained by in vitro techniques and phylogenetic comparison, allow us to propose a model for the structural and functional organization of the rpsA TIR specific for proteobacteria related to E.coli [2].
• A gene was found in Bacillus subtilis which encodes a protein highly homologous to the Escherichia coli rpsA gene product, the S1 ribosomal protein [3].
• To test phylogenetic predictions experimentally, we have generated rpsA'-'lacZ translational fusions by inserting the rpsA TIRs from various gamma-proteobacteria in-frame with the E.coli chromosomal lacZ gene [4].
• Isolation of transducing phage carrying rps T, the structural gene for ribosomal protein S20 [5].

High impact information on rpsA

• To define sequence and structural elements responsible for translational efficiency and autoregulation of the rpsA mRNA, a series of rpsA'-'lacZ chromosomal fusions bearing various mutations in the rpsA TIR was created and tested for beta-galactosidase activity in the absence and presence of excess S1 [2].
• The primary structure of proteins S1, the largest protein component of the Escherichia coli ribosome, has been elucidated by determining the amino acid sequence of the protein (from E. coli MRE600) and the nucleotide sequence of the S1 gene (rpsA, of a K-12 strain) [6].
• Addition of purified protein S1 to a coupled in vitro transcription-translation system caused a specific reduction in the synthesis of the rpsA-lacZ fusion protein [7].
• Synthesis of the fusion protein was repressed about 10-fold when rpsA was supplied in trans on a multicopy plasmid [7].
• Addition of various subdomain fragments of protein S1 to the coupled in vitro system showed that the N-terminal fragment, possessing the ribosome binding domain of protein S1, was able to repress the synthesis of the rpsA-lacZ fusion protein [7].

Biological context of rpsA

• The DNA sequence of the gene rpsA as well as of its neighboring regions has been determined using the dideoxyribonucleotide method [8].
• It was found that there is an "open-reading-frame" of 350 bp which precedes the gene rpsA [8].
• Plasmids with a mutant rpsA gene which do not or only poorly complement the S1 amber mutation cause drastic growth reduction, whereas the overall protein synthesis is affected to different extents depending on the site of the deletion [9].
• We also isolated two mutations mapping in the plasmid-encoded rpsA structural gene: an ochre nonsense mutation in codon 15 of the rpsA gene and a frameshift mutation, deleting the T residue at position +1186 [10].
• The IPTG-induced recombinant protein production resulted in a significant down-regulation of many energy synthesis genes (atp, nuo, cyo), as well as nearly all transcription- and translation-related genes (rpo, rpl, rpm, rps, rrf, rrl, rrs) [11].

Associations of rpsA with chemical compounds

• We found that ppGpp inhibits transcription of stringently controlled genes, rrnE, rpsA, and rplJ, coding for ribosomal RNA, ribosomal protein S1 and L10, respectively, but not that of trp (tryptophan) and lacUV5 (lactose) genes [12].
• Twenty-eight spontaneous and independent mutants, all of them mapping in the rpsA leader region, were isolated as strains that showed higher growth rates, on lactose medium, due to increased synthesis of the rpsA-lacZ' fusion protein [10].
• At the rplJ and rpsA P1 promoters, the addition of ppGpp (in the absence of heparin and nucleotides), results in the dissociation of RNAP from the binary complex [13].

Other interactions of rpsA

• The unfavorable conditions generated by PHB accumulation in the pgi mutant carrying phb resulted in the highest expression of 30S ribosomal protein S1, which ultimately caused a further increase in soluble protein synthesis [14].

Analytical, diagnostic and therapeutic context of rpsA

• By applying the Southern blot technique we compared the structural gene rpsA for ribosomal protein S1 and its preceding sequence from Escherichia coli with nine other bacterial species [15].

References