3fit
FHIT (FRAGILE HISTIDINE TRIAD PROTEIN) IN COMPLEX WITH ADENOSINE/SULFATE AMP ANALOG
Structural highlights
DiseaseFHIT_HUMAN Note=A chromosomal aberration involving FHIT has been found in a lymphoblastoid cell line established from a family with renal cell carcinoma and thyroid carcinoma. Translocation t(3;8)(p14.2;q24.1) with RNF139. Although the 3p14.2 breakpoint has been shown to interrupt FHIT in its 5-prime non-coding region, it is unlikely that FHIT is causally related to renal or other malignancies.[1] Note=Associated with digestive tract cancers. Numerous tumor types are found to have aberrant forms of FHIT protein due to deletions in a coding region of chromosome 3p14.2 including the fragile site locus FRA3B.[2] FunctionFHIT_HUMAN Cleaves A-5'-PPP-5'A to yield AMP and ADP. Possible tumor suppressor for specific tissues.[3] 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 PubMedBACKGROUND: The fragile histidine triad (FHIT) protein is a member of the large and ubiquitous histidine triad (HIT) family of proteins. It is expressed from a gene located at a fragile site on human chromosome 3, which is commonly disrupted in association with certain cancers. On the basis of the genetic evidence, it has been postulated that the FHIT protein may function as a tumor suppressor, implying a role for the FHIT protein in carcinogenesis. The FHIT protein has dinucleoside polyphosphate hydrolase activity in vitro, thus suggesting that its role in vivo may involve the hydrolysis of a phosphoanhydride bond. The structural analysis of FHIT will identify critical residues involved in substrate binding and catalysis, and will provide insights into the in vivo function of HIT proteins. RESULTS: The three-dimensional crystal structures of free and nucleoside complexed FHIT have been determined from multiwavelength anomalous diffraction (MAD) data, and they represent some of the first successful structures to be measured with undulator radiation at the Advanced Photon Source. The structures of FHIT reveal that this protein exists as an intimate homodimer, which is based on a core structure observed previously in another human HIT homolog, protein kinase C interacting protein (PKCI), but has distinctive elaborations at both the N and C termini. Conserved residues within the HIT family, which are involved in the interactions of the proteins with nucleoside and phosphate groups, appear to be relevant for the catalytic activity of this protein. CONCLUSIONS: The structure of FHIT, a divergent HIT protein family member, in complex with a nucleotide analog suggests a metal-independent catalytic mechanism for the HIT family of proteins. A structural comparison of FHIT with PKCI and galactose-1-phosphate uridylyltransferase (GaIT) reveals additional implications for the structural and functional evolution of the ubiquitous HIT family of proteins. MAD analysis of FHIT, a putative human tumor suppressor from the HIT protein family.,Lima CD, D'Amico KL, Naday I, Rosenbaum G, Westbrook EM, Hendrickson WA Structure. 1997 Jun 15;5(6):763-74. PMID:9261067[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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