EIF5B

EIF5B
Identifiers
Aliases	EIF5B, IF2, eukaryotic translation initiation factor 5B
External IDs	OMIM: 606086; MGI: 2441772; HomoloGene: 134613; GeneCards: EIF5B; OMA:EIF5B - orthologs
Gene location (Human) Chr. Chromosome 2 (human)[1] Band 2q11.2 Start 99,337,371 bp[1] End 99,401,326 bp[1]
Gene location (Mouse) Chr. Chromosome 1 (mouse)[2] Band 1|1 B Start 38,037,091 bp[2] End 38,094,660 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in tendon of biceps brachii oocyte secondary oocyte internal globus pallidus myocardium of left ventricle gingival epithelium pericardium pars reticulata cardia external globus pallidus Top expressed in tail of embryo lens genital tubercle zygote epithelium of lens secondary oocyte parotid gland lacrimal gland primary oocyte epiblast More reference expression data BioGPS More reference expression data
Gene ontology Molecular function nucleotide binding protein binding metal ion binding GTP binding hydrolase activity translation initiation factor activity RNA binding GTPase activity Cellular component cytosol nucleus cytoplasm Biological process regulation of translational initiation translational initiation protein biosynthesis Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 9669 226982 Ensembl ENSG00000158417 ENSMUSG00000026083 UniProt O60841 Q05D44 RefSeq (mRNA) NM_015904 NM_198303 RefSeq (protein) NP_056988 NP_938045 Location (UCSC) Chr 2: 99.34 – 99.4 Mb Chr 1: 38.04 – 38.09 Mb PubMed search [3] [4]
Wikidata
View/Edit Human View/Edit Mouse

Eukaryotic translation initiation factor 5B is a protein that in humans is encoded by the EIF5B gene.^[5][6][7] eIF5B is homologous to the bacterial initiation factor 2, sharing a core structure while their involvement in translation initiation differs.^[8]

Function

See also: Eukaryotic translation § Cap-dependent initiation

eIF5B plays an important role in later stages of the translation initiation mechanism. After the start codon has been engaged by the scanning initiation complex, eukaryotic initiation factors eIF1, eIF2, and eIF5 leave the ribosome. Subsequently, eIF5B-GTP is recruited to the ribosome. eIF1A induces rotation of a domain of eIF5B-GTP, which in turn positions the initiator tRNA such that joining of the large ribosomal subunit is possible.^[9] Joining of the large subunit causes hydrolysis of the eIF5B-bound GTP, which accelerates the release of eIF1A from the ribosome.^[10] Dissociation of eIF1A leads to another rearrangement of eIF5B, placing the initiator tRNA in its final position.^[11] The hydrolysis of eIF5B's GTP reduces its affinity to the ribosome, ultimately leading to its dissociation. This concludes the initiation of translation.

References

1. GRCh38: Ensembl release 89: ENSG00000158417 – Ensembl, May 2017
2. GRCm38: Ensembl release 89: ENSMUSG00000026083 – Ensembl, May 2017
3. "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
4. "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
5. Lee JH, Choi SK, Roll-Mecak A, Burley SK, Dever TE (May 1999). "Universal conservation in translation initiation revealed by human and archaeal homologs of bacterial translation initiation factor IF2". Proc Natl Acad Sci U S A. 96 (8): 4342–7. Bibcode:1999PNAS...96.4342L. doi:10.1073/pnas.96.8.4342. PMC 16334. PMID 10200264.
6. Wilson SA, Sieiro-Vazquez C, Edwards NJ, Iourin O, Byles ED, Kotsopoulou E, Adamson CS, Kingsman SM, Kingsman AJ, Martin-Rendon E (Oct 1999). "Cloning and characterization of hIF2, a human homologue of bacterial translation initiation factor 2, and its interaction with HIV-1 matrix". Biochem J. 342. ( Pt 1) (Pt 1): 97–103. doi:10.1042/bj3420097. PMC 1220441. PMID 10432305.
7. "Entrez Gene: EIF5B eukaryotic translation initiation factor 5B".
8. Unbehaun, Anett; Marintchev, Assen; Lomakin, Ivan B.; Didenko, Tatyana; Wagner, Gerhard; Hellen, Christopher U T.; Pestova, Tatyana V. (2007). "Position of eukaryotic initiation factor eIF5B on the 80S ribosome mapped by directed hydroxyl radical probing". The EMBO Journal. 26 (13): 3109–3123. doi:10.1038/sj.emboj.7601751. PMC 1914099. PMID 17568775.
9. Lapointe, Christopher P.; Grosely, Rosslyn; Sokabe, Masaaki; Alvarado, Carlos; Wang, Jinfan; Montabana, Elizabeth; Villa, Nancy; Shin, Byung-Sik; Dever, Thomas E.; Fraser, Christopher S.; Fernández, Israel S.; Puglisi, Joseph D. (2022). "EIF5B and eIF1A reorient initiator tRNA to allow ribosomal subunit joining". Nature. 607 (7917): 185–190. Bibcode:2022Natur.607..185L. doi:10.1038/s41586-022-04858-z. PMC 9728550. PMID 35732735.
10. Fringer, Jeanne M.; Acker, Michael G.; Fekete, Christie A.; Lorsch, Jon R.; Dever, Thomas E. (2007). "Coupled Release of Eukaryotic Translation Initiation Factors 5B and 1A from 80S Ribosomes following Subunit Joining". Molecular and Cellular Biology. 27 (6): 2384–2397. doi:10.1128/MCB.02254-06. PMC 1820483. PMID 17242201.
11. Wang, Jinfan; Wang, Jing; Shin, Byung-Sik; Kim, Joo-Ran; Dever, Thomas E.; Puglisi, Joseph D.; Fernández, Israel S. (2020). "Structural basis for the transition from translation initiation to elongation by an 80S-eIF5B complex". Nature Communications. 11 (1) 5003. Bibcode:2020NatCo..11.5003W. doi:10.1038/s41467-020-18829-3. PMC 7538418. PMID 33024099.

Further reading

• A comprehensive review on eukaryotic translation initiation: Brito Querido, Jailson; Díaz-López, Irene; Ramakrishnan, V. (2024). "The molecular basis of translation initiation and its regulation in eukaryotes". Nature Reviews Molecular Cell Biology. 25 (3): 168–186. doi:10.1038/s41580-023-00624-9. PMID 38052923.
• The structure of an 80S-eIF5B complex: Wang, Jinfan; Wang, Jing; Shin, Byung-Sik; Kim, Joo-Ran; Dever, Thomas E.; Puglisi, Joseph D.; Fernández, Israel S. (2020). "Structural basis for the transition from translation initiation to elongation by an 80S-eIF5B complex". Nature Communications. 11 5003. Bibcode:2020NatCo..11.5003W. doi:10.1038/s41467-020-18829-3. PMID 33024099.
• Marintchev A, Kolupaeva VG, Pestova TV, Wagner G (2003). "Mapping the binding interface between human eukaryotic initiation factors 1A and 5B: a new interaction between old partners". Proc. Natl. Acad. Sci. U.S.A. 100 (4): 1535–40. Bibcode:2003PNAS..100.1535M. doi:10.1073/pnas.0437845100. PMC 149867. PMID 12569173.
• Olsen DS, Savner EM, Mathew A, et al. (2003). "Domains of eIF1A that mediate binding to eIF2, eIF3 and eIF5B and promote ternary complex recruitment in vivo". EMBO J. 22 (2): 193–204. doi:10.1093/emboj/cdg030. PMC 140105. PMID 12514125.