Protein
5'-deoxyadenosine deaminase
Organism
Methanothermobacter thermautotrophicus (strain ATCC 29096 / DSM 1053 / JCM 10044 / NBRC 100330 / Delta H)
Function
Catalyzes the deamination of three SAM-derived enzymatic products, namely 5'-deoxyadenosine, S-adenosyl-L-homocysteine, and 5'-methylthioadenosine, to produce the inosine analogs. Can also deaminate adenosine. The preferred substrate for this enzyme is 5'-deoxyadenosine, but all these substrates are efficiently deaminated. Likely functions in a S-adenosyl-L-methionine (SAM) recycling pathway from S-adenosyl-L-homocysteine (SAH) produced from SAM-dependent methylation reactions. May also be involved in the recycling of 5'-deoxyadenosine, whereupon the 5'-deoxyribose moiety of 5'-deoxyinosine is further metabolized to deoxyhexoses used for the biosynthesis of aromatic amino acids in methanogens.
Similarity
Belongs to the metallo-dependent hydrolases superfamily. MTA/SAH deaminase family.
Sequence
MDNESILITGPEILDAGGIRRGSVLIEDNRIADVSNTLSPGDADTVIDGTGKLLIPGLVNTHTHLSMTLFRGIADDLPLDRWLNDHIWPAEARLNGDYCYAGALLGCIEMIRSGTTSFNDMYFYMDHVARAVEEAGLRCVISHGMIDLGDTEKMTAELRESRRIIKECHGMADDRIRVALGPHSPYTCSEELLKETAALADKNDLMIHIHVSETENEVSEVSRSHGMTPVEYLDEVGVLGPRTVAAHCVWLKDWEIDVLAERDVKVSHNPSSNMKLASGVSPVARLLQRGVNVSLGTDGAASNNNLDMFQEMKTASLLQKVNLEDPTALPAMDVFSMATLNGARALGIDAGLIAPGKLADIVILNTRRPHLTPWRNPPSHTVYSASGADVDTVICDGRILLRDGELEVLEEKYVMELAEAAAAELTG