Reviewed, UniProtKB/Swiss-Prot P0A707 (IF3_ECOLI)

Names and origin

Protein names

Recommended name:
    Translation initiation factor IF-3
Cleaved into the following 2 chains:
    1- Recommended name:
            Translation initiation factor IF-3, N-terminally processed
    2- Recommended name:
            Translation initiation factor IF-3S

Gene names

Name:	infC
Synonyms:	fit
Ordered Locus Names:	b1718, JW5829

Organism

Escherichia coli (strain K12) [Complete proteome] [HAMAP]

Taxonomic identifier

83333 [NCBI]

Taxonomic lineage

Bacteria › Proteobacteria › Gammaproteobacteria › Enterobacteriales › Enterobacteriaceae › Escherichia

Protein attributes

Sequence length	180 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	IF-3 binds to the 30S ribosomal subunit and shifts the equilibrum between 70S ribosomes and their 50S and 30S subunits in favor of the free subunits, thus enhancing the availability of 30S subunits on which protein synthesis initiation begins. HAMAP MF_00080
Subunit structure	Monomer. HAMAP MF_00080
Subcellular location	Cytoplasm. HAMAP MF_00080
Post-translational modification	Phosphorylated on threonine residue(s). Ref.8
Miscellaneous	A short form called IF-3S/IF-3 beta is found both in vivo and in vitro and is probably produced by degradation of the long form IF-3L/IF-3 alpha. HAMAP MF_00080
Sequence similarities	Belongs to the IF-3 family.
Caution	Was originally (Ref.10) thought to control the translation of its own gene by binding to its mRNA; it now seems that discrimination against the AUU start codon is a kinetic effect (Ref.11).

Ontologies

Keywords
Biological process	Protein biosynthesis
Cellular component	Cytoplasm
Ligand	RNA-binding
Molecular function	Initiation factor
PTM	Cleavage on pair of basic residues Methylation Phosphoprotein
Technical term	3D-structure Complete proteome Direct protein sequencing
Gene Ontology (GO)
Biological process	translational initiation Inferred from electronic annotation. Source: HAMAP
Cellular component	cytoplasm Inferred from electronic annotation. Source: UniProtKB-SubCell membrane Inferred from direct assay. Source: UniProtKB
Molecular function	RNA binding Inferred from electronic annotation. Source: UniProtKB-KW translation initiation factor activity Inferred from electronic annotation. Source: HAMAP
Complete GO annotation...

Sequence annotation (Features)

Feature key

Position(s)

Length

Description

Graphical view

Feature identifier

Molecule processing

Chain

1 – 180

180

Translation initiation factor IF-3 HAMAP MF_00080

PRO_0000367498

Initiator methionine

1

1

Removed; alternate HAMAP MF_00080

Chain

2 – 180

179

Translation initiation factor IF-3, N-terminally processed HAMAP MF_00080

PRO_0000014499

Chain

7 – 180

174

Translation initiation factor IF-3S HAMAP MF_00080

PRO_0000364089

Sites

Site

107

1

Important for 30S binding HAMAP MF_00080

Site

110

1

Important for 30S binding HAMAP MF_00080

Amino acid modifications

Modified residue

1

1

N-methylmethionine; in Translation initiation factor IF-3; alternate HAMAP MF_00080

Experimental info

Mutagenesis

107

1

Y → F or L: Reduced ribosome binding. Ref.9

Mutagenesis

110

1

K → R or L: Reduced ribosome binding. Ref.9

Sequence conflict

22

1

Q → E AA sequence Ref.1

Sequence conflict

34 – 36

3

LGI → IGMV AA sequence Ref.1

Sequence conflict

47

1

E → Q AA sequence Ref.1

Sequence conflict

52

1

D → N AA sequence Ref.1

Sequence conflict

61

1

E → Q AA sequence Ref.1

Sequence conflict

87

1

K → E AA sequence Ref.1

Sequence conflict

90

1

V → K AA sequence Ref.1

Sequence conflict

103

1

D → N AA sequence Ref.1

Sequence conflict

105

1

G → N AA sequence Ref.1

Sequence conflict

161

1

F → S in AAA51467. Ref.3

Sequence conflict

178

1

K → Q AA sequence Ref.1

Sequence conflict

180

1

Missing AA sequence Ref.1

Secondary structure

1

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

180

Helix Strand Turn

Details...

Beta strand

92 – 98

7

Helix

104 – 107

4

Helix

109 – 119

11

Beta strand

122 – 128

7

Helix

140 – 152

13

Turn

153 – 155

3

Beta strand

156 – 159

4

Beta strand

171 – 176

6

Sequences

	Sequence		Length	Mass (Da)
	P0A707-1 [UniParc]. Last modified July 21, 1986. Version 1. Checksum: 6120EB6AD42E9ABE	FASTA	180	20,564
	10 20 30 40 50 60 MKGGKRVQTA RPNRINGEIR AQEVRLTGLE GEQLGIVSLR EALEKAEEAG VDLVEISPNA 70 80 90 100 110 120 EPPVCRIMDY GKFLYEKSKS SKEQKKKQKV IQVKEIKFRP GTDEGDYQVK LRSLIRFLEE 130 140 150 160 170 180 GDKAKITLRF RGREMAHQQI GMEVLNRVKD DLQELAVVES FPTKIEGRQM IMVLAPKKKQ

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"The primary structure of the initiation factor IF-3 from Escherichia coli." Brauer D., Wittmann-Liebold B. FEBS Lett. 79:269-275(1977) [PubMed: 330233] [Abstract] Cited for: PROTEIN SEQUENCE, DIFFERENT PROTEIN FORMS, N-TERMINAL METHYLATION. Strain: K.
[2]	"Sequence of a 1.26-kb DNA fragment containing the structural gene for E.coli initiation factor IF3: presence of an AUU initiator codon." Sacerdot C., Fayat G., Dessen P., Springer M., Plumbridge J.A., Grunberg-Manago M., Blanquet S. EMBO J. 1:311-315(1982) [PubMed: 6325158] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
[3]	Miller H.I. Submitted (NOV-1986) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
[4]	"A 570-kb DNA sequence of the Escherichia coli K-12 genome corresponding to the 28.0-40.1 min region on the linkage map." Aiba H., Baba T., Fujita K., Hayashi K., Inada T., Isono K., Itoh T., Kasai H., Kashimoto K., Kimura S., Kitakawa M., Kitagawa M., Makino K., Miki T., Mizobuchi K., Mori H., Mori T., Motomura K. , Nakade S., Nakamura Y., Nashimoto H., Nishio Y., Oshima T., Saito N., Sampei G., Seki Y., Sivasundaram S., Tagami H., Takeda J., Takemoto K., Takeuchi Y., Wada C., Yamamoto Y., Horiuchi T. DNA Res. 3:363-377(1996) [PubMed: 9097039] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: K12 / W3110 / ATCC 27325 / DSM 5911.
[5]	"The complete genome sequence of Escherichia coli K-12." Blattner F.R., Plunkett G. III, Bloch C.A., Perna N.T., Burland V., Riley M., Collado-Vides J., Glasner J.D., Rode C.K., Mayhew G.F., Gregor J., Davis N.W., Kirkpatrick H.A., Goeden M.A., Rose D.J., Mau B., Shao Y. Science 277:1453-1474(1997) [PubMed: 9278503] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: K12 / MG1655 / ATCC 47076.
[6]	"Highly accurate genome sequences of Escherichia coli K-12 strains MG1655 and W3110." Hayashi K., Morooka N., Yamamoto Y., Fujita K., Isono K., Choi S., Ohtsubo E., Baba T., Wanner B.L., Mori H., Horiuchi T. Mol. Syst. Biol. 2:E1-E5(2006) [PubMed: 16738553] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: K12 / W3110 / ATCC 27325 / DSM 5911.
[7]	"Separation of two forms of IF-3 in Escherichia coli by two-dimensional gel electrophoresis." Suryanarayana T., Subramanian A.R. FEBS Lett. 79:264-268(1977) [PubMed: 330232] [Abstract] Cited for: DIFFERENT PROTEIN FORMS. Strain: Al9, CP78, K and MRE600.
[8]	"Phosphorylation of Escherichia coli translation initiation factors by the bacteriophage T7 protein kinase." Robertson E.S., Nicholson A.W. Biochemistry 31:4822-4827(1992) [PubMed: 1534259] [Abstract] Cited for: PHOSPHORYLATION.
[9]	"Structure-function analysis of Escherichia coli translation initiation factor IF3: tyrosine 107 and lysine 110 are required for ribosome binding." Debellis D., Liveris D., Goss D., Ringquist S., Schwartz I. Biochemistry 31:11984-11990(1992) [PubMed: 1457399] [Abstract] Cited for: MUTAGENESIS OF TYR-107 AND LYS-110.
[10]	"AUU-to-AUG mutation in the initiator codon of the translation initiation factor IF3 abolishes translational autocontrol of its own gene (infC) in vivo." Butler J.S., Springer M., Grunberg-Manago M. Proc. Natl. Acad. Sci. U.S.A. 84:4022-4025(1987) [PubMed: 2954162] [Abstract] Cited for: MECHANISM OF TRANSLATION REGULATION.
[11]	"How initiation factors maximize the accuracy of tRNA selection in initiation of bacterial protein synthesis." Antoun A., Pavlov M.Y., Lovmar M., Ehrenberg M. Mol. Cell 23:183-193(2006) [PubMed: 16857585] [Abstract] Cited for: MECHANISM OF TRANSLATION REGULATION.
[12]	"Site-directed mutagenesis and NMR spectroscopic approaches to the elucidation of the structure-function relationships in translation initiation factors IF1 and IF3." Spurio R., Paci M., Pawlik R.T., la Teana A., Digiacco B.V., Pon C.L., Gualerzi C.O. Biochimie 73:1001-1006(1991) [PubMed: 1742345] [Abstract] Cited for: STRUCTURE BY NMR, MUTAGENESIS.
[13]	"1H and 15N resonance assignments and structure of the N-terminal domain of Escherichia coli initiation factor 3." Garcia C., Fortier P.-L., Blanquet S., Lallemand J.-Y., Dardel F. Eur. J. Biochem. 228:395-402(1995) [PubMed: 7705354] [Abstract] Cited for: STRUCTURE BY NMR.
[14]	"Heteronuclear NMR studies of E. coli translation initiation factor IF3. Evidence that the inter-domain region is disordered in solution." Moreau M., de Cock E., Fortier P.-L., Garcia C., Albaret C., Blanquet S., Lallemand J.-Y., Dardel F. J. Mol. Biol. 266:15-22(1997) [PubMed: 9054966] [Abstract] Cited for: STRUCTURE BY NMR.
[15]	"On the global architecture of initiation factor IF3: a comparative study of the linker regions from the Escherichia coli protein and the Bacillus stearothermophilus protein." Hua Y., Raleigh D.P. J. Mol. Biol. 278:871-878(1998) [PubMed: 9614948] [Abstract] Cited for: STRUCTURE BY NMR.
[16]	de Cock E., Blanquet S., Lallemand J.-Y., Dardel F. Submitted (DEC-1998) to the PDB data bank Cited for: STRUCTURE BY NMR OF 90-180.

Cross-references

Sequence databases

EMBLGenBankDDBJ

V00291 Genomic DNA. Translation: CAA23561.1.
K02844 Genomic DNA. Translation: AAA51467.1.
U00096 Genomic DNA. Translation: AAC74788.1.
AP009048 Genomic DNA. Translation: BAA15485.1.

PIR

FIEC3. S13748.

RefSeq

AP_002338.1.
NP_416233.1.

3D structure databases

PDBPDBe

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
2IFE	NMR	-	A	84-180	[»]

ModBase

Search...

Protein-protein interaction databases

IntAct

P0A707. 48 interactions.

PTM databases

PhosSite

P0A707.

2-D gel databases

ECO2DBASE

I019.5. 6TH EDITION.
I020.1. 6TH EDITION.

Genome annotation databases

GeneID

946225.

GenomeReviews

Gene locus JW5829 in contig AP009048_GR.
Gene locus b1718 in contig U00096_GR.

KEGG

ecj:JW5829.
eco:b1718.

Organism-specific databases

EchoBASE

EB0501.

EcoGene

EG10506. infC.

CMR

Search...

Phylogenomic databases

HOGENOM

P0A707.

OMA

P0A707. KEVKMRY.

Enzyme and pathway databases

BioCyc

EcoCyc:EG10506-MON.

Family and domain databases

HAMAP

MF_00080.
[Tree]

InterPro

IPR019813. Translation_initiation_fac3_CS.
IPR001288. Translation_initiation_fac_3.
IPR019815. Translation_initiation_fac_3_C.
IPR019814. Translation_initiation_fac_3_N.
[Graphical view]

Gene3D

G3DSA:3.10.20.80. IF3. 1 hit.
G3DSA:3.30.110.10. IF3. 1 hit.

PANTHER

PTHR10938. IF3. 1 hit.

Pfam

PF00707. IF3_C. 1 hit.
PF05198. IF3_N. 1 hit.
[Graphical view]

ProDom

PD002880. IF3. 1 hit.
[Graphical view] [Entries sharing at least one domain]

TIGRFAMs

TIGR00168. infC. 1 hit.

PROSITE

PS00938. IF3. 1 hit.
[Graphical view]

ProtoNet

Search...

Entry information

Entry name

IF3_ECOLI

Accession

Primary (citable) accession number: P0A707
Secondary accession number(s): P02999, P76905

Entry history

Integrated into UniProtKB/Swiss-Prot:	July 21, 1986
Last sequence update:	July 21, 1986
Last modified:	June 16, 2009
This is version 43 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

HAMAP (High-quality Automated and Manual Annotation of microbial Proteomes)