>TIGR01697 PNPH-PUNA-XAPA inosine guanosine and xanthosine phosphorylase family; InterPro: IPR011268 This entry describes a subset of the phosphorylase family. The entry excludes the methylthioadenosine phosphorylases (MTAP, IPR010044 from INTERPRO), which are believed to play a specific role in the recycling of methionine from methylthioadenosine. This entry consists of three clades of purine phosphorylases based on a neighbour-joining tree using the MTAP family as an out group. The highest-branching clade (IPR011269 from INTERPRO) consists of a group of sequences from both Gram-positive and Gram-negative bacteria which have been shown to act as purine nucleotide phosphorylases but whose physiological substrate and role in vivo remain unknown . Of the two remaining clades, one is xanthosine phosphorylase (XAPA, IPR010943 from INTERPRO); it is limited to certain gammaproteobacteria and constitutes a special purine phosphorylase found in a specialised operon for xanthosine catabolism . The enzyme also acts on the same purines (inosine and guanosine) as the other characterised members of this subfamily, but is only induced when xanthosine must be degraded. The remaining and largest clade consists of purine nucleotide phosphorylases (PNPH, IPR011270 from INTERPRO) from metazoa and bacteria which act primarily on guanosine and inosine, and do not act on adenosine. Sequences from Clostridium and Thermotoga fall between these last two clades and are uncharacterised with respect to substrate range. ; GO: 0004731 purine-nucleoside phosphorylase activity, 0006139 nucleobase nucleoside nucleotide and nucleic acid metabolic process.

Probab=94.98  E-value=0.29  Score=27.56  Aligned_cols=96  Identities=14%  Similarity=0.185  Sum_probs=51.9

Q ss_pred             CHHHHHHHHHHHHHCCCEEEE---------ECCCCCHH-------HHHHHH----HCCCCEEEEEHHHHCCCCHHHHHHH
Q ss_conf             999899999999988989999---------18877645-------488897----2799899971688539994579999
Q gi|254780468|r  840 NPERSRLLLGRLRKIGISLTL---------DDFGTKCS-------LLSYLG----YIPFDTVKFNGSLMTGSTEKRIAIL  899 (963)
Q Consensus       840 ~~~~~~~~~~~l~~~G~~ial---------DdFG~g~s-------sl~~L~----~l~~d~iKiD~sfv~~~~~~~~~~v  899 (963)
T Consensus        74 d~~~vt~PvR~mk~lGv~~lvvTNAAGg~n~~~~~GdLm~i~DHIN~~~~ag~nPLvGpN~~~FG~RFp~l~~AYD~~lr  153 (266)
T TIGR01697        74 DMAAVTFPVRVMKLLGVEILVVTNAAGGLNADFKPGDLMIIKDHINLPGLAGFNPLVGPNDDEFGTRFPDLSNAYDKELR  153 (266)
T ss_pred             CHHHHHHHHHHHHHCCCEEEEEECCCCCCCCCCCCCCEEEEECHHHCCCCCCCCCCCCCCCCCCCCCCCCCCCHHHHHHH
T ss_conf             66677689999986692089997466120678898537997112114400047878698885557899876645679999


Q ss_pred             HHHHHHHHHCCCE-EEEEEC---------CCHHHHHHHHHCCCCEE
Q ss_conf             9999999977980-999703---------99899998998099899
Q gi|254780468|r  900 RSIIPMAKNIETT-IIAKDI---------YGEIDIKELTRMGCDYI  935 (963)
Q Consensus       900 ~sii~~a~~lgi~-viAegV---------E~~~~~~~l~~~G~d~~  935 (963)
T Consensus       154 ~~~~~~A~~~~~~~~l~EGVYv~~~GP~YETPAE~rm~~~lGAD~V  199 (266)
T TIGR01697       154 ALAKDVAKELGVPRLLKEGVYVMVSGPSYETPAEIRMLRILGADAV  199 (266)
T ss_pred             HHHHHHHHHCCCCCEEECCEEEEECCCCCCCHHHHHHHHHHCCCEE
T ss_conf             9999999856898256526888508659526789999998489487