Elongation factor G, mitochondrial

Elongation factor G, mitochondrial (EF-Gmt), encoded by GFM1, is a mitochondrial GTPase essential for translation elongation (UniProt: Q96RP9). It catalyzes the GTP-dependent ribosomal translocation step, coordinating movement of tRNAs, mRNA, and ribosomal conformational changes to advance from the pre-translocational to post-translocational state during protein synthesis. GFM1 does not mediate ribosome disassembly at translation termination.

GFM1 functions within mitochondrial protein synthesis machinery and is associated with combined oxidative phosphorylation deficiency 1 (COXPD1; MIM 609060), a mitochondrial disorder characterized by early-onset hepatoencephalopathy (UniProt: Q96RP9). Defective GFM1 impairs mitochondrial translation capacity and energy metabolism.

In Alzheimer's disease, GFM1 is upregulated in post-mortem AD brain tissue compared to age-matched controls (Chaparral AD proteomics), with a mean log₂ fold-change of 0.62 across one subcellular fraction. This elevation may reflect attempted compensatory enhancement of mitochondrial protein synthesis in response to AD-related bioenergetic stress, though the functional significance remains to be determined.