1a77

FLAP ENDONUCLEASE-1 FROM METHANOCOCCUS JANNASCHIIFLAP ENDONUCLEASE-1 FROM METHANOCOCCUS JANNASCHII

Structural highlights 1a77 is a 1 chain structure with sequence from Methanocaldococcus jannaschii. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [FEN_METJA] Structure-specific nuclease with 5'-flap endonuclease and 5'-3' exonuclease activities involved in DNA replication and repair. During DNA replication, cleaves the 5'-overhanging flap structure that is generated by displacement synthesis when DNA polymerase encounters the 5'-end of a downstream Okazaki fragment. Binds the unpaired 3'-DNA end and kinks the DNA to facilitate 5' cleavage specificity. Cleaves one nucleotide into the double-stranded DNA from the junction in flap DNA, leaving a nick for ligation. Also involved in the base excision repair (BER) pathway. Acts as a genome stabilization factor that prevents flaps from equilibrating into structures that lead to duplications and deletions. Also possesses 5'-3' exonuclease activity on nicked or gapped double-stranded DNA. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Flap endonuclease-1 (FEN-1), a structure specific nuclease, is an essential enzyme for eukaryotic DNA replication and repair. The crystal structure of FEN-1 from Methanococcus jannaschii, determined at 2.0 A resolution, reveals an active site with two metal ions residing on top of a deep cleft where several conserved acidic residues are clustered. Near the active site, a long flexible loop comprised of many basic and aromatic residues forms a hole large enough to accommodate the DNA substrate. Deletion mutations in this loop significantly decreased the nuclease activity and specificity of FEN-1, suggesting that the loop is critical for recognition and cleavage of the junction between single and double-stranded regions of flap DNA. The crystal structure of flap endonuclease-1 from Methanococcus jannaschii.,Hwang KY, Baek K, Kim HY, Cho Y Nat Struct Biol. 1998 Aug;5(8):707-13. PMID:9699635 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Endonuclease 3D structures

spinqualitylabelsall models 1a77, resolution 2.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image