Reverse transcriptase: Difference between revisions
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{{STRUCTURE_1hmv| PDB=1hmv | SIZE=400| SCENE=Reverse_transcriptase/Cv/1 |right|CAPTION=HIV-1 Reverse transcriptase, [[1hmv]] }} | {{STRUCTURE_1hmv| PDB=1hmv | SIZE=400| SCENE=Reverse_transcriptase/Cv/1 |right|CAPTION=HIV-1 Reverse transcriptase, [[1hmv]] }} | ||
[[Reverse transcriptase]] (RT) or RNA-dependent DNA polymerase transcribes single-stranded RNA into double-stranded [[DNA]]. HIV-1 RT is from the human immunodeficiency virus and is a heterodimer of P66 and P51. The images at the left and at the right correspond to one representative RT structure, ''i.e.'' crystal structure of HIV-1 Reverse transcriptase ([[1hmv]]). | [[Reverse transcriptase]] (RT) or RNA-dependent DNA polymerase transcribes single-stranded RNA into double-stranded [[DNA]]. HIV-1 RT is from the human immunodeficiency virus and is a heterodimer of P66 and P51 subchains. The images at the left and at the right correspond to one representative RT structure, ''i.e.'' crystal structure of HIV-1 Reverse transcriptase ([[1hmv]]). There are more details on HIV-1 RT in [[Phl p 2]]. P15 is its RNAse H domain. There are two types of inhibitors for RT: NNRTIs are the non-nucleoside inhibitors, and NRTIs are the nucleoide inhibitors. Being the protein that gives their name to Retroviruses, Reverse Transcriptase is, along with [[Hiv protease|Protease]] and Integrase, the most important part of the protein system involved in the process of infection and reproduction for viruses like HIV, MuLV and AMV. RT has the unusual property of transcribing ssRNA into dsDNA going against the Central Dogma of Molecular Biology. | ||
Since its discovery in 1970, the study of its properties and mechanisms of action have been of high interest among the scientific community due to the unique properties that makes it an important medical target enzyme and important tool for genetic engineering applications like RT-PCR in the construction of cDNA libraries. See also [[Transcription and RNA Processing]]. | Since its discovery in 1970, the study of its properties and mechanisms of action have been of high interest among the scientific community due to the unique properties that makes it an important medical target enzyme and important tool for genetic engineering applications like RT-PCR in the construction of cDNA libraries. See also [[Transcription and RNA Processing]]. | ||
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<applet size='[450,338]' frame='true' align='right' name='Reverse Transcriptase scene='Reverse_transcriptase/Presentation/3' caption='The hand-like two-enzymes-in-one protein that amazingly makes DNA from RNA' /> | <applet size='[450,338]' frame='true' align='right' name='Reverse Transcriptase scene='Reverse_transcriptase/Presentation/3' caption='The hand-like two-enzymes-in-one protein that amazingly makes DNA from RNA' /> | ||
This ''hand-like'' <scene name='Reverse_transcriptase/Chains/2'>heterodimer</scene> protein | This ''hand-like'' <scene name='Reverse_transcriptase/Chains/2'>heterodimer</scene> protein has an usual length of 1000 residues (560 in Chain A and 440 for B), a third of them involved in alpha helices and almost a quarter involved in beta sheets, showing α+β <scene name='Reverse_transcriptase/Secondary/2'>secondary structure</scene> domains. <scene name='Reverse_transcriptase/Chaina/2'>Chain A</scene> has an usual weight of 66KDa whereas <scene name='Reverse_transcriptase/Chainb/2'>Chain B</scene> is around 51KDa. These monomers are derived from the same gene, but p51 lacks the amino acids of one active site and has a different tertiary structure conformation compared to p66. Because of this, p51 is enzymatically inactive. <ref>PMID: 1377403</ref> <!-- [http://www.sciencemag.org.silk.library.umass.edu:2048/cgi/content/abstract/sci;256/5065/1783?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&andorexacttitleabs=and&andorexactfulltext=and&searchid=1&FIRSTINDEX=0&volume=256&firstpage=1783&resourcetype=HWCIT] --> | ||
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