Protein
Probable S-methyl-5'-thioinosine phosphorylase
Organism
Methanocaldococcus jannaschii (strain ATCC 43067 / DSM 2661 / JAL-1 / JCM 10045 / NBRC 100440)
Function
Catalyzes the reversible phosphorylation of S-methyl-5'-thioinosine (MTI) to hypoxanthine and 5-methylthioribose-1-phosphate. Involved in the breakdown of S-methyl-5'-thioadenosine (MTA), a major by-product of polyamine biosynthesis. Catabolism of (MTA) occurs via deamination to MTI and phosphorolysis to hypoxanthine.
Similarity
Belongs to the PNP/MTAP phosphorylase family. MTAP subfamily.
Sequence
MIGIIGGTGIAEILKGDKEEIINTKYGKARVIIDKENEVVLLFRHGVRHNIPPHKINYRANIYALKKLGVERILAINSVGSLKEDLKPGMFFVPNDFIEFTKKREETFYDEGKVVHIDMTDPYCPELRNILKSILDKNNFSYGEGVYVCTEGPRFETKKEIAIYKNWGDVVGMTGYPEVVLARELEMCYVSLCNITNYACGISKNILTVDEVLEKIKEMENKILKVVEDFINYGFGERKCICKDALKHAVIG