Biology:POLRMT

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Short description: Protein-coding gene in the species Homo sapiens


A representation of the 3D structure of the protein myoglobin showing turquoise α-helices.
Generic protein structure example

DNA-directed RNA polymerase, mitochondrial is an enzyme that in humans is encoded by the POLRMT gene.[1][2]

Function

This gene encodes a mitochondrial DNA-directed RNA polymerase. The gene product is responsible for mitochondrial gene expression as well as for providing RNA primers for initiation of replication of the mitochondrial genome. Although this polypeptide has the same function as the three nuclear DNA-directed RNA polymerases, it is more closely related to RNA polymerases of bacteriophage (including T7 RNA polymerase), mitochondrial polymerases of lower eukaryotes as well as chloroplastic RpoT polymerases.[2]

Structure

The structure of the enzyme has been solved. It exhibits an overall structure similar to that of phage RNAP, but the initiation mechanism is different in that it requires initiation factors TFAM (only in mammals) and TFB2M.[3] Elongation requires the elongation factor TEFM.[4] The exact termination process is less understood, but MTERF1 is thought to play a role.[5]

References

  1. "Identification of the gene encoding the human mitochondrial RNA polymerase (h-mtRPOL) by cyberscreening of the Expressed Sequence Tags database". Hum Mol Genet 6 (4): 615–25. Jul 1997. doi:10.1093/hmg/6.4.615. PMID 9097968. 
  2. 2.0 2.1 "Entrez Gene: POLRMT polymerase (RNA) mitochondrial (DNA directed)". https://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=5442. 
  3. Hillen, HS; Morozov, YI; Sarfallah, A; Temiakov, D; Cramer, P (16 November 2017). "Structural Basis of Mitochondrial Transcription Initiation.". Cell 171 (5): 1072–1081.e10. doi:10.1016/j.cell.2017.10.036. PMID 29149603. 
  4. Hillen, Hauke S.; Parshin, Andrey V.; Agaronyan, Karen; Morozov, Yaroslav I.; Graber, James J.; Chernev, Aleksandar; Schwinghammer, Kathrin; Urlaub, Henning et al. (November 2017). "Mechanism of Transcription Anti-termination in Human Mitochondria". Cell 171 (5): 1082–1093.e13. doi:10.1016/j.cell.2017.09.035. PMID 29033127. 
  5. D'Souza, AR; Minczuk, M (20 July 2018). "Mitochondrial transcription and translation: overview.". Essays in Biochemistry 62 (3): 309–320. doi:10.1042/EBC20170102. PMID 30030363. 

Further reading

External links

  • Overview of all the structural information available in the PDB for UniProt: O00411 (Human DNA-directed RNA polymerase, mitochondrial (POLRMT)) at the PDBe-KB.