title: The structure of I-Crel, a group I intron-encoded homing endonuclease.
abstract: The structure of I-Crel provides the first view of a protein encoded by a gene within an intron. This endonuclease recognizes a long DNA site approximately 20 base pairs in length and facilitates the lateral transfer of that intron. The protein exhibits a DNA-binding surface consisting of four antiparallel beta-strands that form a 20 A wide groove which is over 70 A long. The architecture of this fold is different from that of the TATA binding protein, TBP, which also contains an antiparallel beta-saddle. The conserved LAGLIDADG motif, which is found in many mobile intron endonucleases, maturases and inteins, forms a novel helical interface and contributes essential residues to the active site.
authors.affiliation: Fred Hutchinson Cancer Research Center, Division of Basic Sciences, Seattle, Washington 98104, USA.
authors.forename: P J
authors.initials: PJ
authors.lastname: Heath
authors.forename: K M
authors.initials: KM
authors.lastname: Stephens
authors.forename: R J
authors.initials: RJ
authors.lastname: Monnat
authors.forename: B L
authors.initials: BL
authors.lastname: Stoddard
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D017124:Conserved Sequence; D018360:Crystallography, X-Ray; D004247:DNA / Q000378:metabolism*; D004262:DNA Restriction Enzymes; D015246:Deoxyribonuclease EcoRI / Q000737:chemistry / Q000378:metabolism; D015252:Deoxyribonucleases, Type II Site-Specific / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D019281:Dimerization; D005057:Eukaryotic Cells / Q000201:enzymology; D007438:Introns; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017510:Protein Folding; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D011994:Recombinant Proteins; D004247:DNA; D004262:DNA Restriction Enzymes; D015246:Deoxyribonuclease EcoRI; C048901:endodeoxyribonuclease CreI; D015252:Deoxyribonucleases, Type II Site-Specific