IF3 - interference factors : protein factors in Escherichia coli controlling initiation of mRNA translation

Revel, Michel; Pollack, Yaakov; Groner, Yoram; Scheps, Ruth; Inouye, Hiroshi; Berissi, Hanna; Zeller, H.

doi:10.1016/s0300-9084(73)80235-4

Cited by 26 publications

(9 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Different models have been proposed to explain this specificity. As it has a high affinity for RNA [2,4] (and A. J. Wahba, personal communication) factor i has been regarded as a translational repressor, which would thus combine with the initiation site on mRNA and thereby prevent ribosome attachment [4]. However, besides its inhibitory effect on the translation of MS2 RNA, factor i can stimulate the translation of certain cistrons, notably with T7 mRNA [2] and it interacts with initiation factor IF-3, which is required for the binding of natural messengers [3].…”

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

“…Besides initiation factors (for a review, see [i]) a class of additional proteins, designated interference factors, modulate the initiation of protein synthesis on different messengers [2]. Interference factor i belongs to these proteins [2,3]. It inhibits the binding of ribosomes to the coat protein cistron of MS2 RNA but stimulates initiation on other cistrons, notably T7 mRNA [2,3].…”

mentioning

confidence: 99%

“…It inhibits the binding of ribosomes to the coat protein cistron of MS2 RNA but stimulates initiation on other cistrons, notably T7 mRNA [2,3]. On T4 mRNA, although the factor has little effect on the overall amino-acid incorporation, it has been shown that the translation of some products is markedly increased, while the formation of other products is inhibited [2]. Factor i is an acidic protein purified from the high-salt ribosomal wash.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Physical and Functional Homology between Ribosomal Protein S1 and Interference Factor i

Inouye

Pollack

Pétré

1974

European Journal of Biochemistry

View full text Add to dashboard Cite

The homology between the 30‐S ribosomal protein S1 and interference factor i has been investigated. The two proteins are indistinguishable by gel electrophoresis under various conditions. Similar peptides are obtained by cleavage with cyanogen bromide. After labelling with N‐ethylmaleimide, enzymatic digestion yields homologous labelled peptides. This homology is confirmed by immunological data. Characteristic activities of the two proteins have been compared. Both bind polyuridylic acid and stimulate polypeptide synthesis on this template by S1‐depleted ribosomes. Furthermore, S1 inhibits the translation of the coat protein cistron on MS2 RNA, while it has little effect on the overall translation of T4 mRNA, two characteristic properties of interference factor i. S1 and factor i are thus physically and functionally indistinguishable, which suggests that they have identical polypeptide chains. Implications are discussed in terms of function.

show abstract

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Physical and Functional Homology between Ribosomal Protein S1 and Interference Factor i

Inouye

Pollack

Pétré

1974

European Journal of Biochemistry

View full text Add to dashboard Cite

show abstract

“…Although it is a "fractional" protein [i.e., it is present in less than one copy per purified 30S subunit (1)], it is virtually required for the binding and translation of poly(rU) and some natural messenger RNAs (2). Si has also been shown to be the "factor i" protein (3,4) described by Revel et al (5), which inhibits translation in in vitro systems at molar ratios of protein to ribosomes greater than -one (6). This inhibition is apparently due to Si binding the mRNA directly (7) and is most effective with polypyrimidine messengers and least effective with polypurines (8).…”

mentioning

confidence: 99%

Escherichia coli ribosomal protein S1 has two polynucleotide binding sites.

Draper¹,

Pratt²,

Hippel³

1977

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

View full text Add to dashboard Cite

The interaction of Escherichia coli ribosomal protein SI with a variety of RNA and DNA oligomers and polymers has been studied, using both a sedimentation technique and the quenching of intrinsic protein fluorescence upon nucleic acid binding to obtain equilibrium binding parameters. Two polynucleotide binding sites have been detected on SI: site I binds either single-stranded DNA or RNA and does not discriminate between adenine-and cytidine-containing polynucleotides, while site II binding is highly specific for RNA over DNA and shows a marked preference for cytidine polynucleotides over the corresponding adenine-containing species. On the basis of the binding properties of SI to denatured DNA cellulose and poly(rC)cellulose, it is demonstrated that every SI molecule carries both a site I and a site II. Some possible implications of these results for mechanisms of protein synthesis and phage Qft replication are briefly considered.The Escherichia coli ribosomal protein SI has a number of properties which suggest that it plays a very central role in protein synthesis and RNA phage replication. Although it is a "fractional" protein [i.e., it is present in less than one copy per purified 30S subunit (1)], it is virtually required for the binding and translation of poly(rU) and some natural messenger RNAs (2). Si has also been shown to be the "factor i" protein (3, 4) described by Revel et al. (5), which inhibits translation in in vitro systems at molar ratios of protein to ribosomes greater than -one (6). This inhibition is apparently due to Si binding the mRNA directly (7) and is most effective with polypyrimidine messengers and least effective with polypurines (8). Further, the phage Qf3 codes for a replicase that complexes with Si and two other host proteins (3). S1 is required in this complex for recognition and replication of the phage plus strand, but not the complementary minus strand (9).All three of these activities of Si-binding mRNA to the ribosome, inhibiting translation, and aiding replication of Qf RNA-probably depend in some way on the ability of SI to bind polynucleotides. However, the mechanisms by which Si functions in any of these three activities are not really understood in any detail. With regard to the influence of Si on the binding and translation of mRNA, a number of suggestions have been made: (i) that SI forms part of the mRNA binding site on the ribosome (10); (ii) that Si melts a region of secondary structure in the 16S ribosomal RNA to facilitate formation of base pairs between the rRNA and mRNA in initiation of translation (11); (iii) that Si acts to stabilize this same basepaired region (12); and (iv) that Si affects the tertiary structure of mRNA to allow it to bind the 30S subunit (13).Although these hypotheses predict different nucleic acid binding properties for Si, information on the interaction of this protein with nucleic acids is meager. The ability of Si to bindThe costs of publication of this article were defrayed in part by the payment of page charges. This articl...

show abstract

The Mechanism of Translation

Székely

1980

From DNA to Protein

View full text Add to dashboard Cite

IF3 - interference factors : protein factors in Escherichia coli controlling initiation of mRNA translation

Cited by 26 publications

References 26 publications

Physical and Functional Homology between Ribosomal Protein S1 and Interference Factor i

Physical and Functional Homology between Ribosomal Protein S1 and Interference Factor i

Escherichia coli ribosomal protein S1 has two polynucleotide binding sites.

The Mechanism of Translation

Contact Info

Product

Resources

About