Fragile Histidine Triad Gene (FHIT)

, a member of the histidine triad gene family, encodes a diadenosine 5',5'''-P1,P3-triphosphate hydrolase involved in purine metabolism. The gene encompasses the common fragile site FRA3B on chromosome 3, where carcinogen-induced damage can lead to translocations and aberrant transcripts of this gene. In fact, aberrant transcripts from this gene have been found in about half of all esophageal, stomach, and colon carcinomas.The last 21 amino acids at the C terminus of UBC9 appear to be unimportant for its biologic activity, since a UBC9 mutant harboring a deletion of these amino acids could still restore normal growth of yeast containing a temperature-sensitive mutation in the homolog UBC9 gene. Mutational analysis indicated that UBC9 was associated with the C-terminal portion of FHIT.