Reverse transcriptase: Difference between revisions
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==Structure== | ==Structure== | ||
This ''hand-like'' <scene name='Reverse_transcriptase/Chains/1'>heterodimer</scene> protein that has an usual length of 1000 residues (560 in Chain A and 440 for B), the third of them involved in alpha helical and almost a quarter in beta sheets, showing α+β <scene name='Reverse_transcriptase/Secondary/1'>secondary structure</scene> domains; chain A has an usual weight of 66KDa whereas chain B is around 51KDa, those monomers are derived from the same gen but p51 lacks the aminoacids of one active site and has a different tertiary structure conformation compared with | This ''hand-like'' <scene name='Reverse_transcriptase/Chains/1'>heterodimer</scene> protein that has an usual length of 1000 residues (560 in Chain A and 440 for B), the third of them involved in alpha helical and almost a quarter in beta sheets, showing α+β <scene name='Reverse_transcriptase/Secondary/1'>secondary structure</scene> domains; chain A has an usual weight of 66KDa whereas chain B is around 51KDa, those monomers are derived from the same gen but p51 lacks the aminoacids of one active site and has a different tertiary structure conformation compared with p66, for this reason is totally inactive. [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] | ||
==Function== | ==Function== | ||
As a RNA-dependent DNA Polymerase, is able to recognize the initial RNA, transcribe it to ssDNA, cleave the remaining RNA and then build up the dsDNA, to do this the protein has two active catalytic zones. Chain A has the <scene name='Reverse_transcriptase/Fingers/1'>Polymerase active site</scene> that consist of two ''finger-like'' domains, one of them recognizes the initial nucleic acid possibly by h-bonds interactions with phosphate groups of the side chains, then both domains make a conformational change closing the recognition hole to allow the second domain begin the transcription process; this change is allowed by a <scene name='Reverse_transcriptase/Flexible/1'>flexible zone</scene> between the two previous domains that is used as a common pharmaceutical target site in order to prevent this change and by this way inhibit the activity, but this one is the only zone of the Chain A that has non-conserved aminoacids giving the virus more drug resistance. [http://consurfdb.tau.ac.il/chain_selection.php?pdb_ID=1JLB] | As a RNA-dependent DNA Polymerase, is able to recognize the initial RNA, transcribe it to ssDNA, cleave the remaining RNA and then build up the dsDNA, to do this the protein has two active catalytic zones. Chain A has the <scene name='Reverse_transcriptase/Fingers/1'>Polymerase active site</scene> that consist of two ''finger-like'' domains, one of them recognizes the initial nucleic acid possibly by h-bonds interactions with phosphate groups of the side chains, then both domains make a conformational change closing the recognition hole to allow the second domain begin the transcription process; this change is allowed by a <scene name='Reverse_transcriptase/Flexible/1'>flexible zone</scene> between the two previous domains that is used as a common pharmaceutical target site in order to prevent this change and by this way inhibit the activity, but this one is the only zone of the Chain A that has non-conserved aminoacids giving the virus more drug resistance. [http://consurfdb.tau.ac.il/chain_selection.php?pdb_ID=1JLB] | ||