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J Schnier

Publications and source records attributed to J Schnier.

26 records · Page 2Linked to original sources
PubMed1985

Comparative studies on the structural gene for the ribosomal protein S1 in ten bacterial species.

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. We found high homology among the structural genes of E. coli and other gram-negative but not gram-positive bacteria. In contrast, the regulatory sequence preceding the structural gene was not highly conserved among the organisms studied. Cloning and DNA sequence analysis of a 1.2 kb fragment coding for most of the structural gene for S1 from Providencia localized some strongly conserved parts of the DNA sequence, despite the fact that the codon usage showed considerable divergence from that of E. coli.

Amino Acid Sequence↗
PubMed1985

DNA sequence and complementation analysis of a mutation in the rplX gene from Escherichia coli leading to loss of ribosomal protein L24.

A mutation in Escherichia coli leads to the loss of ribosomal protein L24, severely impaired growth, and a temperature-sensitive phenotype. The mutation was shown to be in rplX, the gene for protein L24, and was due to the alteration of an AAA codon to a TAA stop codon at position 61 in rplX that resulted in a 20-amino acid peptide instead of the 104 amino acids of wild-type L24 protein. rplX genes from three temperature-resistant and fast growing pseudorevertants of the mutant were cloned and sequenced. They were found to have different base substitutions in the TAA codon, resulting in the reappearance of a full-sized protein L24 moiety. Complementation of the slow growth in trans could be achieved with several plasmids containing at least the spc promoter and intact L14 and L24 genes. Plasmids containing genes distal to rplX could further stimulate growth, and the wild type arose when the entire spc operon and the alpha operon were present. In all cases, protein L24 was expressed by the plasmids. Therefore, slow growth could be explained by polarity extending to the alpha operon. However, temperature sensitivity could not be complemented by any of the plasmids in trans, although we found that this phenotype was caused by the mutation in the rplX gene.

Base Sequence↗
PubMed1984

Insertion of IS1 into the rpsE gene for ribosomal protein S5 causes cold-sensitivity in Escherichia coli.

The nucleotide sequence of the rpsE gene for the ribosomal protein S5 of a mutant of E. coli showing cold-sensitive growth revealed the presence of an insertion sequence, IS1, near the 3'-end of the gene. This mutant grows very slowly even at the "permissive temperature" (30 degrees C). At temperatures below 20 degrees C, its growth becomes negligible. It is likely that the presence of IS1 disturbs the continued translation of the polycistronic messenger RNA of the "spc-operon" from the point of IS1 insertion downwards, especially at the unfavorable temperatures.

Amino Acid Sequence↗
PubMed1982

Primary structure of Escherichia coli ribosomal protein S1 and of its gene rpsA.

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). The two methods gave results in perfect agreement except of two positions where possible strain specific differences were found. Protein S1 (MRE600) is composed of 557 amino acid residues (no modified amino acids were detected) and has Mr 61,159. The DNA sequence for protein S1 (K-12) suggests 556 amino acid residues. A computer survey of the sequence revealed three regions in S1 with a high degree of internal homology. The ribosome binding domain of S1 (NH2 terminus) does not show any preponderance of basic amino acids. The two cysteine and the majority of tryptophan residues of S1 as well as two od the three homologous regions were located in its middle region which contains the nucleic acid binding domain. The pattern of degenerate codon usage in the S1 gene is nonrandom and similar to that reported for other ribosomal protein genes.

Amino Acid Sequence↗
PubMed1980

Genetic fine structure of the pyrE region containing the genes for ribosomal proteins L28 and L33 in Escherichia coli.

Temperature-sensitive mutants harbouring alterations in ribosomal proteins L28 and L33 have been isolated and used in mapping the genes coding for the two proteins. It was found that they mapped very close to each other and near pyrE at 80.7 min on the E. coli genetic map. The genes affected by the mutations have been concluded to be the structural genes for proteins L28 (rpmB) and L33 (rpmG) by constructing merodiploids heterozygous for pyrE and for the two ribosomal proteins. Various transduction studies with P1kc phages indicate the gene order in this region to be (rpmB, rpmG)-pyrE-spoT-gltC.

Bacterial Proteins↗
PubMed1979

The gene for ribosomal protein L25 (rplY) maps at 47.3 min near nalA in Escherichia coli K-12.

A temperature sensitive mutant, termed JE1306, derived from Escherichia coli strain PA3092 was found to have an alteration in the ribosomal protein L25. Crosses with various Hfr strains and transductions with P1 kc phage have revealed that the mutation maps at 47.3 min between nalA and fpk, in a region where no ribosomal protein gene has so far been located. The gene affected by this mutation is most probably the structural gene for protein L25 (rplY), because a strain heteromerozygous for the region shows both wild type and mutant forms of protein L25.

Chromosome Mapping↗