POLRMT
Description
The POLRMT (RNA polymerase mitochondrial) is a protein-coding gene located on chromosome 19.
POLRMT is a gene that encodes the mitochondrial DNA-directed RNA polymerase, an enzyme responsible for mitochondrial gene expression and replication. The enzyme has a structure similar to phage RNAP but utilizes a different initiation mechanism requiring initiation factors TFAM and TFB2M. The exact termination process is less understood, but MTERF1 is thought to play a role.
POLRMT is a DNA-dependent RNA polymerase that transcribes mitochondrial DNA into RNA using ribonucleoside triphosphates as substrates. It is a component of the mitochondrial transcription initiation complex, composed of TFB2M, TFAM, and POLRMT, which is essential for basal transcription of mitochondrial DNA. In this complex, TFAM recruits POLRMT to a specific promoter, while TFB2M induces structural changes in POLRMT to enable promoter opening and trapping of the non-template DNA strand. POLRMT also has DNA primase activity, catalyzing the synthesis of short RNA primers required for initiating lagging-strand DNA synthesis from the origin of light-strand DNA replication (OriL).
POLRMT is also known as APOLMT, COXPD55, MTRNAP, MTRPOL, h-mtRPOL.
