1FHI

SUBSTRATE ANALOG (IB2) COMPLEX WITH THE FRAGILE HISTIDINE TRIAD PROTEIN, FHIT

1FHI の概要

• エントリーDOI: 10.2210/pdb1fhi/pdb
• 分子名称: FRAGILE HISTIDINE TRIAD PROTEIN, P1-P2-METHYLENE-P3-THIO-DIADENOSINE TRIPHOSPHATE (3 entities in total)
• 機能のキーワード: nucleotide-binding protein, cancer, diadenosine triphosphate hydrolase, histidine triad, tumor suppressor
• 由来する生物種: Homo sapiens (human)
• 細胞内の位置: Cytoplasm: P49789
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 17656.70

構造登録者

Pace, H.C.,Garrison, P.N.,Barnes, L.D.,Draganescu, A.,Rosler, A.,Blackburn, G.M.,Siprashvili, Z.,Croce, C.M.,Huebner, K.,Brenner, C. (登録日: 1997-12-11, 公開日: 1998-06-17, 最終更新日: 2024-05-22)

主引用文献

Pace, H.C.,Garrison, P.N.,Robinson, A.K.,Barnes, L.D.,Draganescu, A.,Rosler, A.,Blackburn, G.M.,Siprashvili, Z.,Croce, C.M.,Huebner, K.,Brenner, C.
Genetic, biochemical, and crystallographic characterization of Fhit-substrate complexes as the active signaling form of Fhit.
Proc.Natl.Acad.Sci.USA, 95:5484-5489, 1998

PubMed Abstract: Alterations in the FHIT gene at 3p14.2 occur as early and frequent events in the development of several common human cancers. The ability of human Fhit-negative cells to form tumors in nude mice is suppressed by stable reexpression of Fhit protein. Fhit protein is a diadenosine P1,P3-triphosphate (ApppA) hydrolase whose fungal and animal homologs form a branch of the histidine triad (HIT) superfamily of nucleotide-binding proteins. Because the His-96 --> Asn substitution of Fhit, which retards ApppA hydrolase activity by seven orders of magnitude, did not block tumor-suppressor activity in vivo, we determined whether this mutation affected ApppA binding or particular steps in the ApppA catalytic cycle. Evidence is presented that His-96 --> Asn protein binds ApppA well and forms an enzyme-AMP intermediate extremely poorly, suggesting that Fhit-substrate complexes are the likely signaling form of the enzyme. The cocrystal structure of Fhit bound to Ado-p-CH2-p-ps-Ado (IB2), a nonhydrolyzable ApppA analog, was refined to 3.1 A, and the structure of His-96 --> Asn Fhit with IB2 was refined to 2.6 A, revealing that two ApppA molecules bind per Fhit dimer; identifying two additional adenosine-binding sites on the dimer surface; and illustrating that His-98 is positioned to donate a hydrogen bond to the scissile bridging oxygen of ApppA substrates. The form of Fhit bound to two ApppA substrates would present to the cell a dramatically phosphorylated surface, prominently displaying six phosphate groups and two adenosine moieties in place of a deep cavity lined with histidines, arginines, and glutamines.

PubMed: 9576908
DOI: 10.1073/pnas.95.10.5484

実験手法

X-RAY DIFFRACTION (3.1 Å)