ID MTNN_HAEIE Reviewed; 229 AA. AC A5UCP4; DT 20-JAN-2009, integrated into UniProtKB/Swiss-Prot. DT 10-JUL-2007, sequence version 1. DT 02-SEP-2026, entry version 96. DE RecName: Full=5'-methylthioadenosine/S-adenosylhomocysteine nucleosidase {ECO:0000255|HAMAP-Rule:MF_01684}; DE Short=MTA/SAH nucleosidase {ECO:0000255|HAMAP-Rule:MF_01684}; DE Short=MTAN {ECO:0000255|HAMAP-Rule:MF_01684}; DE EC=3.2.2.9 {ECO:0000255|HAMAP-Rule:MF_01684}; DE AltName: Full=5'-deoxyadenosine nucleosidase {ECO:0000255|HAMAP-Rule:MF_01684}; DE Short=DOA nucleosidase {ECO:0000255|HAMAP-Rule:MF_01684}; DE Short=dAdo nucleosidase {ECO:0000255|HAMAP-Rule:MF_01684}; DE AltName: Full=5'-methylthioadenosine nucleosidase {ECO:0000255|HAMAP-Rule:MF_01684}; DE Short=MTA nucleosidase {ECO:0000255|HAMAP-Rule:MF_01684}; DE AltName: Full=S-adenosylhomocysteine nucleosidase {ECO:0000255|HAMAP-Rule:MF_01684}; DE Short=AdoHcy nucleosidase {ECO:0000255|HAMAP-Rule:MF_01684}; DE Short=SAH nucleosidase {ECO:0000255|HAMAP-Rule:MF_01684}; DE Short=SRH nucleosidase {ECO:0000255|HAMAP-Rule:MF_01684}; GN Name=mtnN {ECO:0000255|HAMAP-Rule:MF_01684}; GN OrderedLocusNames=CGSHiEE_05950; OS Haemophilus influenzae (strain PittEE). OC Bacteria; Pseudomonadati; Pseudomonadota; Gammaproteobacteria; OC Pasteurellales; Pasteurellaceae; Haemophilus. OX NCBI_TaxID=374930; RN [1] RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. RC STRAIN=PittEE; RX PubMed=17550610; DOI=10.1186/gb-2007-8-6-r103; RA Hogg J.S., Hu F.Z., Janto B., Boissy R., Hayes J., Keefe R., Post J.C., RA Ehrlich G.D.; RT "Characterization and modeling of the Haemophilus influenzae core and RT supragenomes based on the complete genomic sequences of Rd and 12 clinical RT nontypeable strains."; RL Genome Biol. 8:R103.1-R103.18(2007). CC -!- FUNCTION: Catalyzes the irreversible cleavage of the glycosidic bond in CC both 5'-methylthioadenosine (MTA) and S-adenosylhomocysteine CC (SAH/AdoHcy) to adenine and the corresponding thioribose, 5'- CC methylthioribose and S-ribosylhomocysteine, respectively. Also cleaves CC 5'-deoxyadenosine, a toxic by-product of radical S-adenosylmethionine CC (SAM) enzymes, into 5-deoxyribose and adenine. {ECO:0000255|HAMAP- CC Rule:MF_01684}. CC -!- CATALYTIC ACTIVITY: CC Reaction=S-adenosyl-L-homocysteine + H2O = S-(5-deoxy-D-ribos-5-yl)-L- CC homocysteine + adenine; Xref=Rhea:RHEA:17805, ChEBI:CHEBI:15377, CC ChEBI:CHEBI:16708, ChEBI:CHEBI:57856, ChEBI:CHEBI:58195; EC=3.2.2.9; CC Evidence={ECO:0000255|HAMAP-Rule:MF_01684}; CC -!- CATALYTIC ACTIVITY: CC Reaction=S-methyl-5'-thioadenosine + H2O = 5-(methylsulfanyl)-D-ribose CC + adenine; Xref=Rhea:RHEA:13617, ChEBI:CHEBI:15377, CC ChEBI:CHEBI:16708, ChEBI:CHEBI:17509, ChEBI:CHEBI:78440; EC=3.2.2.9; CC Evidence={ECO:0000255|HAMAP-Rule:MF_01684}; CC -!- CATALYTIC ACTIVITY: CC Reaction=5'-deoxyadenosine + H2O = 5-deoxy-D-ribose + adenine; CC Xref=Rhea:RHEA:29859, ChEBI:CHEBI:15377, ChEBI:CHEBI:16708, CC ChEBI:CHEBI:17319, ChEBI:CHEBI:149540; EC=3.2.2.9; CC Evidence={ECO:0000255|HAMAP-Rule:MF_01684}; CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:29860; CC Evidence={ECO:0000255|HAMAP-Rule:MF_01684}; CC -!- PATHWAY: Amino-acid biosynthesis; L-methionine biosynthesis via salvage CC pathway; S-methyl-5-thio-alpha-D-ribose 1-phosphate from S-methyl-5'- CC thioadenosine (hydrolase route): step 1/2. {ECO:0000255|HAMAP- CC Rule:MF_01684}. CC -!- SIMILARITY: Belongs to the PNP/UDP phosphorylase family. MtnN CC subfamily. {ECO:0000255|HAMAP-Rule:MF_01684}. CC --------------------------------------------------------------------------- CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms CC Distributed under the Creative Commons Attribution (CC BY 4.0) License CC --------------------------------------------------------------------------- DR EMBL; CP000671; ABQ98545.1; -; Genomic_DNA. DR AlphaFoldDB; A5UCP4; -. DR SMR; A5UCP4; -. DR KEGG; hip:CGSHiEE_05950; -. DR HOGENOM; CLU_031248_2_2_6; -. DR UniPathway; UPA00904; UER00871. DR GO; GO:0005829; C:cytosol; IEA:TreeGrafter. DR GO; GO:0008782; F:adenosylhomocysteine nucleosidase activity; IEA:UniProtKB-UniRule. DR GO; GO:0008930; F:methylthioadenosine nucleosidase activity; IEA:UniProtKB-UniRule. DR GO; GO:0009164; P:nucleoside catabolic process; IEA:InterPro. DR CDD; cd09008; MTAN; 1. DR FunFam; 3.40.50.1580:FF:000001; MTA/SAH nucleosidase family protein; 1. DR Gene3D; 3.40.50.1580; Nucleoside phosphorylase domain; 1. DR HAMAP; MF_01684; Salvage_MtnN; 1. DR InterPro; IPR010049; MTA_SAH_Nsdase. DR InterPro; IPR000845; Nucleoside_phosphorylase_d. DR InterPro; IPR035994; Nucleoside_phosphorylase_sf. DR NCBIfam; TIGR01704; MTA_SAH-Nsdase; 1. DR NCBIfam; NF004079; PRK05584.1; 1. DR PANTHER; PTHR46832; 5'-METHYLTHIOADENOSINE/S-ADENOSYLHOMOCYSTEINE NUCLEOSIDASE; 1. DR PANTHER; PTHR46832:SF1; 5'-METHYLTHIOADENOSINE_S-ADENOSYLHOMOCYSTEINE NUCLEOSIDASE; 1. DR Pfam; PF01048; PNP_UDP_1; 1. DR SUPFAM; SSF53167; Purine and uridine phosphorylases; 1. PE 3: Inferred from homology; KW Amino-acid biosynthesis; Hydrolase; Methionine biosynthesis. FT CHAIN 1..229 FT /note="5'-methylthioadenosine/S-adenosylhomocysteine FT nucleosidase" FT /id="PRO_0000359306" FT ACT_SITE 12 FT /note="Proton acceptor" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01684" FT ACT_SITE 197 FT /note="Proton donor" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01684" FT BINDING 78 FT /ligand="substrate" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01684" FT BINDING 152 FT /ligand="substrate" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01684" FT BINDING 173..174 FT /ligand="substrate" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01684" SQ SEQUENCE 229 AA; 24087 MW; 3BFE0089810B4C5E CRC64; MKIGIVGAMA QEVEILKNLM ADRTETRVAS AVIFEGKING KDVVLLQSGI GKVAAAIGTT ALLQLAKPDL VINTGSAGGV AKGLKVGDIV ISDETRYHDA DVTAFGYEKG QLPANPAAFL SDKKLADLAQ EIAEKQGQSV KRGLICSGDS FINSEDKITQ IKADFPNVTG VEMEATAIAQ VCYAFNVPFV VVRAISDGGD GKASISFEEF LPLAAKQSSA LVLEMIDRL //