1vyb
From Proteopedia
Endonuclease domain of human LINE1 ORF2p
Structural highlights
FunctionLORF2_HUMAN Has a reverse transcriptase activity required for target-primed reverse transcription of the LINE-1 element mRNA, a crucial step in LINE-1 retrotransposition. Has also an endonuclease activity that allows the introduction of nicks in the chromosomal target DNA. Cleaves DNA in AT-rich regions between a 5' stretch of purines and a 3' stretch of pyrimidines, corresponding to sites of LINE-1 integration in the genome.[1] [2] [3] Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe human L1 endonuclease (L1-EN) is encoded by the non-LTR retrotransposon LINE-1 (L1). L1 is responsible for more than 1.5 million retrotransposition events in the history of the human genome, contributing more than a quarter to human genomic DNA (L1 and Alu elements). L1-EN is related to the well-understood human DNA repair endonuclease APE1, and its nicking specificity is a major determinant for retrotransposon integration site selection. The crystal structure of human L1 endonuclease is the first of a retrotransposon-encoded protein and a prototype for retrotransposon-encoded endonucleases involved in target-primed reverse transcription. Structure-based endonuclease alignments reveal a conserved threonine in addition to previously identified invariant residues and suggest that DNA recognition proceeds via the accommodation of an extrahelical nucleotide within a pocket of the enzyme. The present analysis will help to refine phylogenetic and functional relationships among metal-dependent phosphohydrolases and provides a basis for manipulating non-LTR retrotransposon integration site selection. Crystal structure of the targeting endonuclease of the human LINE-1 retrotransposon.,Weichenrieder O, Repanas K, Perrakis A Structure. 2004 Jun;12(6):975-86. PMID:15274918[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
|