Structural highlights
Function
RT67_ECOLX Reverse transcriptase (RT) component of antiviral defense system retron Ec67, minimally composed of a non-coding RNA (ncRNA) and this RT. Expression of these 2 elements confers protection against bacteriophage T5. At multiplicity of infection (MOI) of 0.02 cultures grow normally when infected with T5 without collapsing, at MOI 2 cultures enter growth stasis (PubMed:33157039). Responsible for synthesis of msDNA-Ec67 (a branched molecule with RNA linked by a 2',5'-phosphodiester bond to ssDNA). The retron transcript serves as primer (from a conserved internal G residue) and template for the reaction, and codes for the RT (PubMed:1378431, PubMed:1692831, PubMed:2466332). Can use other retrons as substrate (msDNA-Mx162 and msDNA-Ec86). Also able to synthesize DNA from a DNA template at least in vitro, although the enzyme is less active with a DNA template (PubMed:1692831).[1] [2] [3] [4]
References
- ↑ Hsu MY, Eagle SG, Inouye M, Inouye S. Cell-free synthesis of the branched RNA-linked msDNA from retron-Ec67 of Escherichia coli. J Biol Chem. 1992 Jul 15;267(20):13823-9 PMID:1378431
- ↑ Lampson BC, Viswanathan M, Inouye M, Inouye S. Reverse transcriptase from Escherichia coli exists as a complex with msDNA and is able to synthesize double-stranded DNA. J Biol Chem. 1990 May 25;265(15):8490-6 PMID:1692831
- ↑ Lampson BC, Sun J, Hsu MY, Vallejo-Ramirez J, Inouye S, Inouye M. Reverse transcriptase in a clinical strain of Escherichia coli: production of branched RNA-linked msDNA. Science. 1989 Feb 24;243(4894 Pt 1):1033-8. PMID:2466332 doi:10.1126/science.2466332
- ↑ Millman A, Bernheim A, Stokar-Avihail A, Fedorenko T, Voichek M, Leavitt A, Oppenheimer-Shaanan Y, Sorek R. Bacterial Retrons Function In Anti-Phage Defense. Cell. 2020 Dec 10;183(6):1551-1561.e12. doi: 10.1016/j.cell.2020.09.065. Epub, 2020 Nov 5. PMID:33157039 doi:https://dx.doi.org/10.1016/j.cell.2020.09.065