1plj
From Proteopedia
CRYSTALLOGRAPHIC STUDIES ON P21H-RAS USING SYNCHROTRON LAUE METHOD: IMPROVEMENT OF CRYSTAL QUALITY AND MONITORING OF THE GTPASE REACTION AT DIFFERENT TIME POINTS
Structural highlights
Disease[RASH_HUMAN] Defects in HRAS are the cause of faciocutaneoskeletal syndrome (FCSS) [MIM:218040]. A rare condition characterized by prenatally increased growth, postnatal growth deficiency, mental retardation, distinctive facial appearance, cardiovascular abnormalities (typically pulmonic stenosis, hypertrophic cardiomyopathy and/or atrial tachycardia), tumor predisposition, skin and musculoskeletal abnormalities.[1] [2] [3] [4] [5] [6] [7] Defects in HRAS are the cause of congenital myopathy with excess of muscle spindles (CMEMS) [MIM:218040]. CMEMS is a variant of Costello syndrome.[8] Defects in HRAS may be a cause of susceptibility to Hurthle cell thyroid carcinoma (HCTC) [MIM:607464]. Hurthle cell thyroid carcinoma accounts for approximately 3% of all thyroid cancers. Although they are classified as variants of follicular neoplasms, they are more often multifocal and somewhat more aggressive and are less likely to take up iodine than are other follicular neoplasms. Note=Mutations which change positions 12, 13 or 61 activate the potential of HRAS to transform cultured cells and are implicated in a variety of human tumors. Defects in HRAS are a cause of susceptibility to bladder cancer (BLC) [MIM:109800]. A malignancy originating in tissues of the urinary bladder. It often presents with multiple tumors appearing at different times and at different sites in the bladder. Most bladder cancers are transitional cell carcinomas. They begin in cells that normally make up the inner lining of the bladder. Other types of bladder cancer include squamous cell carcinoma (cancer that begins in thin, flat cells) and adenocarcinoma (cancer that begins in cells that make and release mucus and other fluids). Bladder cancer is a complex disorder with both genetic and environmental influences. Note=Defects in HRAS are the cause of oral squamous cell carcinoma (OSCC).[9] Defects in HRAS are the cause of Schimmelpenning-Feuerstein-Mims syndrome (SFM) [MIM:163200]. A disease characterized by sebaceous nevi, often on the face, associated with variable ipsilateral abnormalities of the central nervous system, ocular anomalies, and skeletal defects. Many oral manifestations have been reported, not only including hypoplastic and malformed teeth, and mucosal papillomatosis, but also ankyloglossia, hemihyperplastic tongue, intraoral nevus, giant cell granuloma, ameloblastoma, bone cysts, follicular cysts, oligodontia, and odontodysplasia. Sebaceous nevi follow the lines of Blaschko and these can continue as linear intraoral lesions, as in mucosal papillomatosis.[10] Function[RASH_HUMAN] Ras proteins bind GDP/GTP and possess intrinsic GTPase activity.[11] [12] [13] 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 parameters affecting the crystal quality of complexes between p21(H-ras) and caged GTP have been investigated. The use of pure diastereomers of caged GTP complexed to the more stable p21(G12P)' mutant of p21 and the addition of n-octyl-beta-D-glucopyranoside improved the reproducibility and decreased the mosaicity of the crystals significantly. Furthermore, the crystallization technique was changed from the batch method to the sitting-drop technique. With the availability of a larger yield of well ordered crystals, it was possible to extend the time-resolved crystallographic investigations on p21(H-ras). A structure of p21(G12P)':GTP could be obtained 2 min after photolytic removal of the cage group and led to the identification of a previously unidentified conformation for the so-called catalytically active loop L4. The refinement of five data sets collected within 2 min at different times (2-4, 11-13, 20-22, 30-32 and 90-92 min) after the initiation of the intrinsic GTPase reaction of the protein indicates that the synchrotron Laue method can be used to detect small structural changes and alternative conformations, but is presently limited in the analysis of larger rearrangements since these produce diffuse and broken electron density. Crystallographic studies on p21(H-ras) using the synchrotron Laue method: improvement of crystal quality and monitoring of the GTPase reaction at different time points.,Scheidig AJ, Sanchez-Llorente A, Lautwein A, Pai EF, Corrie JE, Reid GP, Wittinghofer A, Goody RS Acta Crystallogr D Biol Crystallogr. 1994 Jul 1;50(Pt 4):512-20. PMID:15299412[14] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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