Role of G factor in protein synthesis. Studies on a temperature- sensitive Escherichia coli mutant with an altered G factor

Felicetti, L.; Tocchini‐Valentini, Glauco P.; Grenzi, Matteo

doi:10.1021/bi00836a044

Cited by 19 publications

(6 citation statements)

References 21 publications

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“…One is a tem perature-sensitive E. coli mutant (219,220), and the other is a fusidic acid resistant mutant (220,221 ). One is a tem perature-sensitive E. coli mutant (219,220), and the other is a fusidic acid resistant mutant (220,221 ).…”

Section: Lucas-len Ard and Lipmannmentioning

confidence: 99%

Protein Biosynthesis

Lucas‐Lenard¹,

Lipmann²

1971

Annu. Rev. Biochem.

453

119

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Section: Lucas-len Ard and Lipmannmentioning

confidence: 99%

Protein Biosynthesis

Lucas‐Lenard¹,

Lipmann²

1971

Annu. Rev. Biochem.

453

119

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“…In Figure 2, the positions of G and T factors, assayed by previously described techniques,22 23 are indicated on the column elution profile. If instead of S-100, T factor (from its column peak) was added to reaction mixtures, no activity was observed unless a sample from a column fraction containing G factor was also included (this is shown in Fig.…”

mentioning

confidence: 99%

Ribonuclease v of Escherichia Coli, I. Dependence on Ribosomes and Translocation

Kuwano

Kwan

Apirion

et al. 1969

Proc. Natl. Acad. Sci. U.S.A.

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Abstract.-A new RNase activity, tentatively named RNase V, was found in cell-free extracts of E. coli. This activity requires ribosomes, G and T factors, tRNA, K+ or NH4+, Mg2+, GTP, and a sulfhydryl compound to degrade poly U, poly A, T4 phage mRNA, or E. coli mRNA. RNase V is specific for mRNA; it does not attack ribosomal RNA. It is inhibited by antibiotics that decrease breakdown of mRNA in vivo, such as chloramphenicol and streptomycin, and by such agents as 5'-#, 'y-methylene-guanosine triphosphate, and fusidic acid, which inhibit ribosome-dependent GTPase and translocation of ribosomes along mRNA. The evidence suggests that RNase V is either an integral part of the ribosome or is tightly associated with it, and that it selectively degrades mRNA in intact cells.The instability of messenger RNA is central to many questions in biology.-What determines how long a molecule of mRNA persists, and how does it break down? The mechanisms have remained unknown, though recent work has suggested that at least in some cases, both functional inactivation and degradation of mRNA proceed from the 5' to the 3' end of the molecule.1' 2 A clue to the mechanism and regulation of mRNA breakdown has been obtained from studies of rnRNA metabolism in antibiotic-treated cultures of E. coli.3-5 When protein synthesis is blocked by chloramphenicol or streptomycin, mIRNA synthesis continues, but mRNA breakdown is inhibited. This implies that mRNA breakdown is linked to some feature of protein synthesis. Therefore, we have looked for an RNase activity linked to the protein synthetic machinery. Here we report the finding of such an activity, tentatively designated RNase V, and describe some of its properties. It is specific for mRNA and requires ribosomes, tRNA, T factor, and G factor.6"9 RNase V is inhibited by chloramphenicol and streptomycin, which block mRNA breakdown in vivo, [3][4][5] and by fusidic acid4-5 10-13 and 5'-3,By-methylene-guanosine triphosphate"4 which block translocation. These properties suggest that RNase V is an mRNase in the cell.Materials and Methods.-Strains: The strains used were all derived from E. coli K12.N11 (met-his-ura-RNase I10-) was isolated from strain D10 (met-RNase Ilo-

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“…A bacteri;:-like G factor specific for 70 S ribosomes and differing from the corresponding 80 S-specific T 2 factor has been found in the cytoplasm of Prototheca zopfii, yeast [6] and rat liver [ 11 ]. From our findings it appears possible that such factors, which cannot function in the cytoplasm because of the absence of 70 S ribosomes, have been released from mitochondria or, in the case of Prototheca, from chloroplasts during extraction.…”

Section: Discussionmentioning

confidence: 48%