Premium
Characterization of an IMP Cyclohydrolase in Haloferax volcanii
Author(s) -
Pasier Michelle,
Sarisky Catherine
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.573.32
Subject(s) - haloferax volcanii , biochemistry , halophile , archaea , enzyme , biology , complementation , inosine monophosphate , biosynthesis , nucleotide , chemistry , gene , genetics , bacteria , mutant
Purine biosynthesis is a fundamental metabolic pathway present in nearly all life forms. Archaea, unlike bacteria and eukaryotes, do not universally conserve enzymes in this pathway. Additionally, some archaeal purine biosynthetic enzymes are not homologous to non‐archaeal enzymes. The final reaction in de novo purine synthesis pathway is the conversion of 5‐formamidoimidazole‐4‐carboxamide ribotide (FAICAR) to inosine‐5′‐monophosphate (IMP). In Haloferax volcanii , a halophilic archaeon, this reaction is catalyzed by an archaeal‐type IMP cyclohydrolase. The genome of H. volcanii is sequenced, but the characterization of its genes has not yet been completed. HVO_0011 was cloned, overexpressed in E. coli , and shown to have IMP cyclohydrolase activity in a HPLC‐based assay. Work is in progress to purify the enzyme and to demonstrate complementation in an E. coli knock‐out system, but the work has been challenging due to unusually high salt requirements. The H. volcanii enzyme is the fourth archaeal PurO‐type IMP cyclohydrolase to be functionally characterized, and the first from a halophile.