RNA chain growth-rate in Escherichia coli

Bremer, H. J.; Yuan, Dorothy

doi:10.1016/0022-2836(68)90404-x

Cited by 174 publications

(54 citation statements)

References 6 publications

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“…A similar observation has already been made by Burgess [15] concerning E. coli RNA polymerase. This is consistent with the finding that the number of growing RNA chains is greater, the faster the generation time [23].…”

Section: Discussionsupporting

confidence: 92%

Simultaneous Purification of Escherichia coli Termination Factor Rho, RNAase III and RNAase H

Darlix¹

1975

Eur J Biochem

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This communication describes a method for the simultaneous purification of Escherichia coli termination factor rho, RNAase I11 and RNAase H, which is rapid, reproducible and high in yield. Depending on how cells are grown 0.5 to 1 mg of RNAase 111, 1 to 2 mg of RNAase H and 1 to 2 mg of rho are obtained from 100 g wet cells. RNAase I11 and rho are pure proteins, and RNAase H 80 % pure.In addition it is shown that pure RNAase I11 degrades only RNA . RNA duplexes, and is responsible for the sizing of early T7 mRNA. The active form of RNAase I11 is composed of two identical subunits having a molecular weight of 23 500. Native RNAase H which specifically hydrolyses the RNA moiety of an RNA . DNA hybrid, is a single polypeptide chain with a molecular weight of 21 000. The amino acid composition of termination factor rho is also reported.Besides DNA polymerase and RNA polymerase that respectively replicate and transcribe the DNA, there exist other proteins like RNAase H, rho and RNAase I11 that also play important roles in the synthesis of DNA and RNA [l -71.RNAase H specifically degrades the RNA moiety of an RNA . DNA hybrid, and then could eliminate the primer RNA for DNA replication [l]. Termination factor rho dissociates the ternary transcription complex RNA . RNA-polymerase . DNA at the terminator of a gene, and modulates DNA transcription [7,8].RNAase I11 hydrolyses only RNA . RNA duplexes, and is responsible for the maturation of various RNAs, like early T7RNA and Escherichia coli ribosomal RNA [6,9,10]

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Section: Discussionsupporting

confidence: 92%

Simultaneous Purification of Escherichia coli Termination Factor Rho, RNAase III and RNAase H

Darlix¹

1975

Eur J Biochem

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“…To see whether an mRNA segment like the ICS of the gnd gene is present in zwf, we used the RNA folding algorithm of Zucker and Stiegler (59) to examine the secondary structure of zwf mRNA molecules, increasing in length by 10 ever, the segment from -61 to -12, which is just upstream from the Shine-Dalgarno core sequence, folded into an extended secondary structure with a free energy of -14.4 kcal (-60.25 kJ)/mol (data not shown). Possibly, this structure is the substrate for endonucleases that process the mRNA to the species whose 5' ends are at -53 and -45.…”

Section: Resultsmentioning

confidence: 99%

Molecular characterization of the Escherichia coli K-12 zwf gene encoding glucose 6-phosphate dehydrogenase

Rowley

Wolf

1991

J Bacteriol

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In Escheyichia coli K-12, expression of zwf, the gene for glucose 6-phosphate dehydrogenase, is coordinated with the cellular growth rate and induced by superoxide-generating agents. To initiate the study of the molecular mechanisms regulating its expression, the gene was cloned and its DNA sequence was determined. The 5' ends of zwfmRNA isolated from cells growing in glucose and acetate minimal media were mapped. The map was complex in that transcripts mapped to -45, -52, and -62, with respect to the beginning of the coding sequence. Three analytical methods were used to search the DNA sequence for putative promoters. Only one sequence for a promoter recognized by the r70 form of RNA polymerase was found by all three search routines that could be aligned with a mapped transcript, indicating that the other transcripts arise by processing of the mRNA. A computer-assisted search did not reveal a thermodynamically stable long-range mRNA secondary structure that is capable of sequestering the translation initiation region, which suggests that growth-ratedependent regulation of glucose 6-phosphate dehydrogenase level may not be carried out by a mechanism similar to the one for the gene (gnd) for 6-phosphogluconate dehydrogenase. The DNA segment between the -10 hexamer and the start point of transcription resembles the discriminator sequence of stable RNA genes, which has been implicated in stringent control and growth-rate-dependent regulation.The oxidative branch of the pentose phosphate pathway provides ribose for nucleoside biosynthesis and NADPH for reductive biosyntheses (15,20). The two dehydrogenases of this pathway are glucose 6-phosphate dehydrogenase (G6PD; EC 1.1.1.49) and 6-phosphogluconate dehydrogenase (6PGD; EC 1.1.1.44). In Escherichia coli, the specific activities of these enzymes increase in proportion to growth rate during steady-state growth on different carbon sources (56). Although the growth rate dependence of the level of these two enzymes resembles that of the components of the translational apparatus, they are not part of the same regulatory network. After a nutritional shiftup, the accumulation rate of ribosomal components increases immediately, whereas the accumulation rate of G6PD and 6PGD has the same kinetics as that of total protein, i.e., increasing only after a lag (16). Thus, the mechanism(s) underlying the growth-rate-dependent regulation of zwf and gnd, which encode G6PD and 6PGD, respectively, may be common to other nonribosomal proteins whose levels also increase with increasing growth rate.Studies of the control of gnd expression point to an interesting mechanism. Regulation is exerted at a posttranscriptional step and requires sequences within the 6PGD coding region (3, 4). The internal regulatory site, which lies between codons 71 and 74, is complementary to the translation initiation region on gnd mRNA (12). This internal complementary sequence (ICS) appears to function as a cis-acting antisense RNA by forming a long-range secondary structure that sequesters the ribosome bin...

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“…Possibly, there is a single major mRNA covering all this region even including CQS, though it is equally possible that several fairly large transcription units are involved. A single RNA species of this length would probably take as much as 5-10 min to transcribe (Bremer & Yuan, 1968). Not surprisingly, considering that 4C31 mRNA has a half-life of only 1-1.5 min (Rodriguez et al, 1986), only degraded molecules were detectable.…”

Section: Discussionmentioning

confidence: 99%

Global transcription pattern of C31 after induction of a Streptomyces coelicolor lysogen at different growth stages

Súarez

Clayton²,

Rodrı́guez³

et al. 1992

Journal of General Microbiology

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Using two complementary strategies for low-resolution Sl mapping, the global pattern of (bC31 transcription was studied after induction of thermoinducible (bC31 lysogens of Streptomyces coelicolor A3(2). A complex pattern of early transcripts was seen, with a peak of abundance at about 10 min post-induction. Nearly all of these transcripts were from DNA located to the right of the c (repressor) gene and to the left of the attP site: a region of about 14 kb. Early transcription was also observed immediately to the left of the c gene. The c gene itself was also induced, with an earlier expression peak (about 5 min post-induction). Primary late transcripts were generally relatively long, but degraded. They apparently corresponded to most of the 18 kb region to the left of the c gene. Some shorter and more persistent late transcripts corresponded to DNA close to or overlapping the cos site. Large late transcripts from a region close to the left-hand end of the (bC31 genome showed evidence of processing to more stable, smaller RNA species. A failure of older cultures (more than 12 h old) to be induced productively was correlated with a much longer period of early transcription, reduced late transcription, failure to synthesize a major virion protein, and failure to package (bC31 DNA. Moreover, heat treatment of the older lysogenic cultures did not result in the 6C31-dependerd shut-down of host rRNA transcription previously observed for young cultures (Rodriguez et al

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RNA chain growth-rate in Escherichia coli

Cited by 174 publications

References 6 publications

Simultaneous Purification of Escherichia coli Termination Factor Rho, RNAase III and RNAase H

Simultaneous Purification of Escherichia coli Termination Factor Rho, RNAase III and RNAase H

Molecular characterization of the Escherichia coli K-12 zwf gene encoding glucose 6-phosphate dehydrogenase

Global transcription pattern of C31 after induction of a Streptomyces coelicolor lysogen at different growth stages

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