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Crystal structure of C83A mutant of Human acidic fibroblast growth factor
Structural highlights
FunctionFGF1_HUMAN Plays an important role in the regulation of cell survival, cell division, angiogenesis, cell differentiation and cell migration. Functions as potent mitogen in vitro.[1] [2] [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 PubMedThe 22 members of the mouse/human fibroblast growth factor (FGF) family of proteins contain a conserved cysteine residue at position 83 (numbering scheme of the 140-residue form of FGF-1). Sequence and structure information suggests that this position is a free cysteine in 16 members and participates as a half-cystine in at least 3 (and perhaps as many as 6) other members. While a structural role as a half-cystine provides a stability basis for possible selective pressure, it is less clear why this residue is conserved as a free cysteine (although free buried thiols can limit protein functional half-life). To probe the structural role of the free cysteine at position 83 in FGF-1, we constructed Ala, Ser, Thr, Val, and Ile mutations and determined their effects on structure and stability. These results show that position 83 in FGF-1 is thermodynamically optimized to accept a free cysteine. A second cysteine mutation was introduced into wild-type FGF-1 at adjacent position Ala66, which is known to participate as a half-cystine with position 83 in FGF-8, FGF-19, and FGF-23. Results show that, unlike position 83, a free cysteine at position 66 destabilizes FGF-1; however, upon oxidation, a near-optimal disulfide bond is formed between Cys66 and Cys83, resulting in approximately 14 kJ/mol of increased thermostability. Thus, while the conserved free cysteine at position 83 in the majority of the FGF proteins may have a principal role in limiting functional half-life, evidence suggests that it is a vestigial half-cystine. Structural basis of conserved cysteine in the fibroblast growth factor family: evidence for a vestigial half-cystine.,Lee J, Blaber M J Mol Biol. 2009 Oct 16;393(1):128-39. Epub 2009 Aug 13. PMID:19683004[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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