1lwt
From Proteopedia
Crystal structure of the intein homing endonuclease PI-SceI bound to its substrate DNA (Ca2+ free)
Structural highlights
Function[VATA_YEAST] Catalytic subunit of the peripheral V1 complex of vacuolar ATPase. V-ATPase (vacuolar ATPase) is responsible for acidifying a variety of intracellular compartments in eukaryotic cells. It is an electrogenic proton pump that generates a proton motive force of 180 mV, inside positive and acidic, in the vacuolar membrane vesicles. It may participate in maintenance of cytoplasmic Ca(2+) homeostasis. This is a catalytic subunit.[1] PI-SceI is an endonuclease that can cleave at a site present in a VMA1 allele that lacks the derived endonuclease segment of the open reading frame; cleavage at this site only occurs during meiosis and initiates "homing", a genetic event that converts a VMA1 allele lacking VDE into one that contains it.[2] 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 PubMedThe first X-ray structures of an intein-DNA complex, that of the two-domain homing endonuclease PI-SceI bound to its 36-base pair DNA substrate, have been determined in the presence and absence of Ca(2+). The DNA shows an asymmetric bending pattern, with a major 50 degree bend in the endonuclease domain and a minor 22 degree bend in the splicing domain region. Distortions of the DNA bound to the endonuclease domain cause the insertion of the two cleavage sites in the catalytic center. DNA binding induces changes in the protein conformation. The two overlapping non-identical active sites in the endonucleolytic center contain two Ca(+2) ions that coordinate to the catalytic Asp residues. Structure analysis indicates that the top strand may be cleaved first. Crystal structure of the intein homing endonuclease PI-SceI bound to its recognition sequence.,Moure CM, Gimble FS, Quiocho FA Nat Struct Biol. 2002 Oct;9(10):764-70. PMID:12219083[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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