Elongation factor 4, also known as ribosomal back-translocase LepA, is present in bacteria and mitochondria, and is required for accurate and efficient protein synthesis under certain stress conditions []. The yeast counterpart of LepA is known as GUF1 []. GUF1 promotes protein synthesis and acts as a fidelity factor of the translation reaction, by catalysing a one-codon backward translocation of tRNAs on improperly translocated ribosomes.This entry represents translation factor GUF1 homologues from plants and cyanobacteria (chloroplastic and from organellar chromatophores).
The elongation factor 4 (LepA or GUF1 in Saccaromyces) is a GTP-binding membrane protein related to EF-G and EF-Tu. LepA is a noncanonical GTPase that has an unknown function. It is highly conserved and present in bacteria, mitochondria, and chloroplasts []. LepA contains domains that are homologous to EF-G domain I, II, III, V. However, it also contains a C-terminal domain (CTD) that is not homologous to any region in EF-G. This entry represents the unique C-terminal region of LepA []. The CTD of LepA may play a primary role in back translocation by providing additional binding interactions with a back-translocated tRNA [].
Elongation factor 4, also known as ribosomal back-translocase LepA, is required for accurate and efficient protein synthesis under certain stress conditions. Its function is not clear. However, it may act as a fidelity factor of the translation reaction, by catalysing a one-codon backward translocation of tRNAs on improperly translocated ribosomes. Back-translocation proceeds from a post-translocation (POST) complex to a pre-translocation (PRE) complex, thus giving elongation factor G a second chance to translocate the tRNAs correctly [, ]. Elongation factor 4 binds to ribosomes in a GTP-dependent manner. The eukaryotic homologue is known as GUF1 and promotes protein synthesis in chloroplasts and mitochondria [].
The elongation factor 4 (LepA or GUF1 in Saccaromyces) is a GTP-binding membrane protein related to EF-G and EF-Tu. LepA is a noncanonical GTPase that has an unknown function. It is highly conserved and present in bacteria, mitochondria, and chloroplasts []. LepA contains domains that are homologous to EF-G domain I, II, III, V. However, it also contains a C-terminal domain (CTD) that is not homologous to any region in EF-G. This entry represents the unique C-terminal region of LepA []. The CTD of LepA may play a primary role in back translocation by providing additional binding interactions with a back-translocated tRNA [].
Elongation factor 4, also known as ribosomal back-translocase LepA, is required for accurate and efficient protein synthesis under certain stress conditions. Its function is not clear. However, it may act as a fidelity factor of the translation reaction, by catalysing a one-codon backward translocation of tRNAs on improperly translocated ribosomes. Back-translocation proceeds from a post-translocation (POST) complex to a pre-translocation (PRE) complex, thus giving elongation factor G a second chance to translocate the tRNAs correctly [, ]. Elongation factor 4 binds to ribosomes in a GTP-dependent manner. The eukaryotic homologue is known as GUF1 and promotes protein synthesis in chloroplasts and mitochondria [].EF4 has six domains, of which four (I, II, III, and V) are homologous to corresponding domains in EF-G [, , ]. This entry represents domain IV of EF4, homologous to domain V of EF-G.
