Escherichia coli K-12 substr. MG1655 Polypeptide: protein chain initiation factor IF-1

Gene: infA Accession Numbers: EG10504 (EcoCyc), b0884, ECK0875

Synonyms: bypA1, IF1

Regulation Summary Diagram: ?

Regulation summary diagram for infA

IF-1 is one of three translation initiation factors in E. coli and is essential for viability [Cummings94, Baba06]. Its functional role has not been fully elucidated; a collection of mutants was generated to attempt to determine the function of IF-1 [Croitoru04]. It was suggested that the essential function of IF-1 and IF-3 may be to minimize the fraction of ribosomes lacking an initiator tRNA [Antoun06].

IF-1 binds to the ribosomal A site [Moazed95], which may suggest a function in translational fidelity; such a function could not be shown [Croitoru05]. Certain mutations in 16S rRNA disrupt binding of IF-1 to the 30S subunit [Dahlquist00], and a model where IF-1 modulates specific conformational change during initiation has been suggested [Dahlquist00]. IF-1 enhances the dissociation rate of 70S ribosomes apparently by stimulating the activity of IF-3 [DottavioMartin79, GrunbergManago75, Pon84]. IF-1 stimulates the association of IF-2 with the 30S subunit [Stringer77, Moreno99] and the ability of IF-2 to stimulate template-dependent binding of aminoacyl-tRNAs to the ribosome [Canonaco86]. IF-1 is released from the ribosome during association of the 30S and 50S subunits [Celano88].

The solution structure of IF-1 has been determined, and residues that are involved in interactions with the 30S ribosomal subunit have been identified. The structure appears similar to the oligomer-binding (OB) fold family of proteins [Sette97].

Expression of infA is growth rate-controlled at the level of transcription [Cummings91]. Transcription of infA is increased by cold shock via activation of the distal promoter [Ko06].

Reviews: [Boelens02, Laursen05]

Locations: cytosol

Map Position: [925,448 <- 925,666] (19.95 centisomes, 72°)
Length: 219 bp / 72 aa

Molecular Weight of Polypeptide: 8.25 kD (from nucleotide sequence)

Unification Links: ASAP:ABE-0003005 , CGSC:17674 , DIP:DIP-48250N , EchoBASE:EB0499 , EcoGene:EG10504 , EcoliWiki:b0884 , OU-Microarray:b0884 , PortEco:infA , PR:PRO_000023012 , Pride:P69222 , Protein Model Portal:P69222 , RefSeq:NP_415404 , RegulonDB:EG10504 , SMR:P69222 , String:511145.b0884 , UniProt:P69222

Relationship Links: InterPro:IN-FAMILY:IPR004368 , InterPro:IN-FAMILY:IPR006196 , InterPro:IN-FAMILY:IPR012340 , InterPro:IN-FAMILY:IPR022967 , PDB:Structure:1AH9 , PDB:Structure:1ZO1 , Pfam:IN-FAMILY:PF01176 , Prosite:IN-FAMILY:PS50832 , Smart:IN-FAMILY:SM00316

GO Terms:

Biological Process: GO:0006412 - translation Inferred by computational analysis [UniProtGOA11a, GOA06]
GO:0006413 - translational initiation Inferred by computational analysis [UniProtGOA11a, GOA06, GOA01a]
Molecular Function: GO:0005515 - protein binding Inferred from experiment [Rajagopala14]
GO:0043022 - ribosome binding Inferred from experiment [Moazed95]
GO:0003723 - RNA binding Inferred by computational analysis [GOA01a]
GO:0003743 - translation initiation factor activity Inferred by computational analysis [UniProtGOA11a, GOA06, GOA01a]
Cellular Component: GO:0005829 - cytosol Inferred from experiment Inferred by computational analysis [DiazMejia09, Ishihama08]
GO:0005737 - cytoplasm Inferred by computational analysis [UniProtGOA11, UniProtGOA11a, GOA06]

MultiFun Terms: information transfer protein related translation

Essentiality data for infA knockouts: ?

Growth Medium Growth? T (°C) O2 pH Osm/L Growth Observations
LB Lennox No 37 Aerobic 7   No [Baba06, Comment 1]

Last-Curated ? 21-Jul-2006 by Keseler I , SRI International

Sequence Features

Protein sequence of protein chain initiation factor IF-1 with features indicated

Feature Class Location Citations Comment
Cleavage-of-Initial-Methionine 1
[Pon79, Wasinger98, UniProt11]
UniProt: Removed.
Conserved-Region 2 -> 72
UniProt: S1-like;
Chain 2 -> 72
UniProt: Translation initiation factor IF-1;

Gene Local Context (not to scale): ?

Gene local context diagram

Transcription Units:

Transcription-unit diagram

Transcription-unit diagram


10/20/97 Gene b0884 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG10504; confirmed by SwissProt match.


Antoun06: Antoun A, Pavlov MY, Lovmar M, Ehrenberg M (2006). "How initiation factors tune the rate of initiation of protein synthesis in bacteria." EMBO J 25(11);2539-50. PMID: 16724118

Baba06: Baba T, Ara T, Hasegawa M, Takai Y, Okumura Y, Baba M, Datsenko KA, Tomita M, Wanner BL, Mori H (2006). "Construction of Escherichia coli K-12 in-frame, single-gene knockout mutants: the Keio collection." Mol Syst Biol 2;2006.0008. PMID: 16738554

Boelens02: Boelens R, Gualerzi CO (2002). "Structure and function of bacterial initiation factors." Curr Protein Pept Sci 3(1);107-19. PMID: 12370015

Canonaco86: Canonaco MA, Calogero RA, Gualerzi CO (1986). "Mechanism of translational initiation in prokaryotes. Evidence for a direct effect of IF2 on the activity of the 30 S ribosomal subunit." FEBS Lett 207(2);198-204. PMID: 3533628

Celano88: Celano B, Pawlik RT, Gualerzi CO (1988). "Interaction of Escherichia coli translation-initiation factor IF-1 with ribosomes." Eur J Biochem 178(2);351-5. PMID: 3061814

Croitoru04: Croitoru V, Bucheli-Witschel M, Hagg P, Abdulkarim F, Isaksson LA (2004). "Generation and characterization of functional mutants in the translation initiation factor IF1 of Escherichia coli." Eur J Biochem 271(3);534-44. PMID: 14728680

Croitoru05: Croitoru VV, Bucheli-Witschel M, Isaksson LA (2005). "In vivo involvement of mutated initiation factor IF1 in gene expression control at the translational level." FEBS Lett 579(5);995-1000. PMID: 15710381

Cummings91: Cummings HS, Sands JF, Foreman PC, Fraser J, Hershey JW (1991). "Structure and expression of the infA operon encoding translational initiation factor IF1. Transcriptional control by growth rate." J Biol Chem 266(25);16491-8. PMID: 1909328

Cummings94: Cummings HS, Hershey JW (1994). "Translation initiation factor IF1 is essential for cell viability in Escherichia coli." J Bacteriol 176(1);198-205. PMID: 8282696

Dahlquist00: Dahlquist KD, Puglisi JD (2000). "Interaction of translation initiation factor IF1 with the E. coli ribosomal A site." J Mol Biol 299(1);1-15. PMID: 10860719

DiazMejia09: Diaz-Mejia JJ, Babu M, Emili A (2009). "Computational and experimental approaches to chart the Escherichia coli cell-envelope-associated proteome and interactome." FEMS Microbiol Rev 33(1);66-97. PMID: 19054114

DottavioMartin79: Dottavio-Martin D, Suttle DP, Ravel JM (1979). "The effects of initiation factors IF-1 and IF-3 on the dissociation of Escherichia coli 70 S ribosomes." FEBS Lett 97(1);105-10. PMID: 367813

GOA01a: GOA, DDB, FB, MGI, ZFIN (2001). "Gene Ontology annotation through association of InterPro records with GO terms."

GOA06: GOA, SIB (2006). "Electronic Gene Ontology annotations created by transferring manual GO annotations between orthologous microbial proteins."

GrunbergManago75: Grunberg-Manago M, Dessen P, Pantaloni D, Godefroy-Colburn T, Wolfe AD, Dondon J (1975). "Light-scattering studies showing the effect of initiation factors on the reversible dissociation of Escherichia coli ribosomes." J Mol Biol 94(3);461-78. PMID: 1100842

Ishihama08: Ishihama Y, Schmidt T, Rappsilber J, Mann M, Hartl FU, Kerner MJ, Frishman D (2008). "Protein abundance profiling of the Escherichia coli cytosol." BMC Genomics 9;102. PMID: 18304323

Ko06: Ko JH, Lee SJ, Cho B, Lee Y (2006). "Differential promoter usage of infA in response to cold shock in Escherichia coli." FEBS Lett 580(2);539-44. PMID: 16405963

Laursen05: Laursen BS, Sorensen HP, Mortensen KK, Sperling-Petersen HU (2005). "Initiation of protein synthesis in bacteria." Microbiol Mol Biol Rev 69(1);101-23. PMID: 15755955

Moazed95: Moazed D, Samaha RR, Gualerzi C, Noller HF (1995). "Specific protection of 16 S rRNA by translational initiation factors." J Mol Biol 248(2);207-10. PMID: 7739034

Moreno99: Moreno JM, Drskjotersen L, Kristensen JE, Mortensen KK, Sperling-Petersen HU (1999). "Characterization of the domains of E. coli initiation factor IF2 responsible for recognition of the ribosome." FEBS Lett 455(1-2);130-4. PMID: 10428486

Pon79: Pon CL, Wittmann-Liebold B, Gualerzi C (1979). "Structure--function relationships in Escherichia coli initiation factors. II. Elucidation of the primary structure of initiation factor IF-1." FEBS Lett 101(1);157-60. PMID: 376343

Pon84: Pon CL, Gualerzi CO (1984). "Mechanism of protein biosynthesis in prokaryotic cells. Effect of initiation factor IF1 on the initial rate of 30 S initiation complex formation." FEBS Lett 175(2);203-7. PMID: 6383865

Rajagopala14: Rajagopala SV, Sikorski P, Kumar A, Mosca R, Vlasblom J, Arnold R, Franca-Koh J, Pakala SB, Phanse S, Ceol A, Hauser R, Siszler G, Wuchty S, Emili A, Babu M, Aloy P, Pieper R, Uetz P (2014). "The binary protein-protein interaction landscape of Escherichia coli." Nat Biotechnol 32(3);285-90. PMID: 24561554

Sette97: Sette M, van Tilborg P, Spurio R, Kaptein R, Paci M, Gualerzi CO, Boelens R (1997). "The structure of the translational initiation factor IF1 from E.coli contains an oligomer-binding motif." EMBO J 16(6);1436-43. PMID: 9135158

Stringer77: Stringer EA, Sarkar P, Maitra U (1977). "Function of initiation factor 1 in the binding and release of initiation factor 2 from ribosomal initiation complexes in Escherichia coli." J Biol Chem 252(5);1739-44. PMID: 320213

UniProt09: UniProt Consortium (2009). "UniProt version 15.8 released on 2009-10-01 00:00:00." Database.

UniProt11: UniProt Consortium (2011). "UniProt version 2011-06 released on 2011-06-30 00:00:00." Database.

UniProtGOA11: UniProt-GOA (2011). "Gene Ontology annotation based on the manual assignment of UniProtKB Subcellular Location terms in UniProtKB/Swiss-Prot entries."

UniProtGOA11a: UniProt-GOA (2011). "Gene Ontology annotation based on manual assignment of UniProtKB keywords in UniProtKB/Swiss-Prot entries."

Wasinger98: Wasinger VC, Humphery-Smith I (1998). "Small genes/gene-products in Escherichia coli K-12." FEMS Microbiol Lett 169(2);375-82. PMID: 9868784

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Please cite the following article in publications resulting from the use of EcoCyc: Nucleic Acids Research 41:D605-12 2013
Page generated by SRI International Pathway Tools version 19.0 on Fri Oct 9, 2015, biocyc11.