This family contains one sequence of known function Human mitochondrial transcription termination factor (mTERF) the rest of the family consists of hypothetical proteins none of which have any functional information. mTERF is a multizipper protein possessing three putative leucine zippers one of which is bipartite. The protein binds DNA as a monomer . The leucine zippers are not implicated in a dimerisation role as in other leucine zippers .
This entry represents the mitochondrial/chloroplastic transcription termination factors (MTERFs). In humans four MTERFs have been identified (MTERF1-4). MTERF1 was first identified as a factor responsible for terminating heavy strand transcription at a specific site at the leu-tRNA, thereby modulating the ratio of mitochondrial ribosomal RNA to mRNA [PUBMED:2752429]. Later, MTERF1 was found to stimulate transcriptional initiation [PUBMED:19366610] and appeared to be in the control of mitochondrial replication pausing [PUBMED:17884915]. From a structural study, it binds to dsDNA containing the termination sequence and unwinds the DNA molecule, promoting base eversion, which is critical for transcription termination [PUBMED:20550934].
Fernandez-Silva P, Martinez-Azorin F, Micol V, Attardi G; , EMBO J 1997;16:1066-1079.: The human mitochondrial transcription termination factor (mTERF) is a multizipper protein but binds to DNA as a monomer, with evidence pointing to intramolecular leucine zipper interactions. PUBMED:9118945 EPMC:9118945.