An evolutionary ratchet leading to loss of elongation factors in eukaryotes
2014 (English)In: BMC Evolutionary Biology, ISSN 1471-2148, Vol. 14, 35- p.Article in journal (Refereed) Published
Background: The GTPase eEF1A is the eukaryotic factor responsible for the essential, universal function of aminoacyl-tRNA delivery to the ribosome. Surprisingly, eEF1A is not universally present in eukaryotes, being replaced by the paralog EFL independently in multiple lineages. The driving force behind this unusually frequent replacement is poorly understood. Results: Through sequence searching of genomic and EST databases, we find a striking association of eEF1A replacement by EFL and loss of eEF1A's guanine exchange factor, eEF1Ba, suggesting that EFL is able to spontaneously recharge with GTP. Sequence conservation and homology modeling analyses indicate several sequence regions that may be responsible for EFL's lack of requirement for eEF1Ba. Conclusions: We propose that the unusual pattern of eEF1A, eEF1Ba and EFL presence and absence can be explained by a ratchet-like process: if either eEF1A or eEF1Ba diverges beyond functionality in the presence of EFL, the system is unable to return to the ancestral, eEF1A:eEFBa-driven state.
Place, publisher, year, edition, pages
2014. Vol. 14, 35- p.
eEF1A, EFL, eEF1B, Ribosome, Elongation factor, GTPase, GEF, Molecular evolution, Eukaryotes
Biochemistry and Molecular Biology
IdentifiersURN: urn:nbn:se:umu:diva-88968DOI: 10.1186/1471-2148-14-35ISI: 000334457000001OAI: oai:DiVA.org:umu-88968DiVA: diva2:718594