In prokaryotes, Shine-Dalgarno (SD) sequences, nucleotides upstream from start codons on messenger RNAs (mRNAs) that are complementary to ribosomal RNA (rRNA), facilitate the initiation of protein synthesis. The location of SD sequences relative to start codons and the stability of the hybridization between the mRNA and the rRNA correlate with the rate of synthesis. Thus, accurate characterizat...

In Escherichia coli, the phosphorylation and dephosphorylation of isocitrate dehydrogenase (IDH) are catalyzed by a bifunctional protein kinase/phosphatase. We have determined the nucleotide sequence of aceK, the gene encoding IDH kinase/phosphatase. This gene consists of a single open reading frame of 1,734 base pairs preceded by a Shine-Dalgarno ribosome-binding site. Examination of the deduc...

The nucleotide sequence of a 2224 bp region of the Escherichia co l i chromosome that c a r r i e s the LexA regulated recN gene has been determined. A region of 1701 nucleot ides encoding a polypeptide of 567 amino acids with a predicted molecular weight of 63,599 was iden t i f i ed as the most probable sequence for the recN s t r u c t u r a l gene. The proposed i n i t i a t i o n codon i s...

Several features of the translational attenuation model of ermC regulation were tested. This model predicts two possible secondary structures for the leader of the ermC transcript and requires that the leader contains two Shine-Dalgarno (SD) sequences. The ribosome binding site for a leader peptide (SD1) is predicted to be accessible, whereas that for the rRNA methylase protein that confers ery...

T4 DNA topoisomerase is a type II enzyme and is thought to be required for normal T4 DNA replication T4 gene 39 codes for the largest of the three subunits of T4 DNA topoisomerase. I have determined the nucleotide sequence of a region of 2568 nucleotides of T4 DNA which includes gene 39. The location of the gene was established by the identification of the first fifteen amino acids in the large...

The 5'-untranslated leader sequences of several plant RNA viruses, and a portion of the 5'-leader of an animal retrovirus, were tested for their ability to enhance expression of contiguous open reading frames for chloramphenicol acetyltransferase (CAT) or beta-glucuronidase (GUS) in tobacco mesophyll protoplasts, Escherichia coli and oocytes of Xenopus laevis. Translation of capped or uncapped ...

Analyses of genome reduction in obligate bacterial symbionts typically focus on the removal and retention of protein-coding regions, which are subject to ongoing inactivation and deletion. However, these same forces operate on intergenic spacers (IGSs) and affect their contents, maintenance, and rates of evolution. IGSs comprise both non-coding, non-functional regions, including decaying pseudo...

Bacteriophage Mu is a highly efficient transposon which requires the products of the Mu A and B genes in order to transpose at a normal frequency. We have determined the nucleotide sequence of the B gene as well as that of the A-B intergenic region upstream of B. The protein product of the gene contains 312 amino acids and has a predicted molecular weight of 35,061. As expected, there do not ap...

In prokaryotes, translation initiation is believed to occur through an interaction between the 3΄ tail of a 16S rRNA and a corresponding Shine-Dalgarno (SD) sequence in the 5΄ untranslated region (UTR) of an mRNA. However, some genes lack SD sequences (non-SD genes), and the fraction of non-SD genes in a genome varies depending on the prokaryotic species. To elucidate non-SD translation initiat...