>TIGR01855 IMP_synth_hisH imidazole glycerol phosphate synthase, glutamine amidotransferase subunit; InterPro: IPR010139 Imidazole glycerol phosphate synthetase (IGPS) is a key metabolic enzyme, which links amino acid and nucleotide biosynthesis: it catalyses the closure of the imidazole ring within histidine biosynthesis (fifth step), and provides the substrate for de novo purine biosynthesis. IGPS consists of two different subunits: HisH, a glutamine amidotransferase (glutaminase), and HisF, a synthase (cyclase). HisH functions to provide a source of nitrogen, which is required for the synthesis of histidine and purines. In the HisH glutaminase reaction, the hydrolysis of glutamine yields ammonia, which is then used by HisF in the subsequent synthase reaction. The X-ray structure of the HisH/HisF heterodimer of IGPS reveals a putative tunnel for the transfer of ammonia from HisH to HisF via a (beta-alpha)8 barrel fold within HisF that abuts HisH . Ammonia tunnels connect the glutaminase and synthase active sites. HisH belongs to a large group of enzymes found in diverse and fundamental anabolic pathways. These enzymes share a common domain, referred to as the type-I glutamine amidotransferase (GATase) domain, which can occur either as single polypeptides (as with HisH) or as domains of large multifunctional proteins.; GO: 0016763 transferase activity transferring pentosyl groups, 0000105 histidine biosynthetic process, 0005737 cytoplasm.

Probab=99.65 E-value=5.1e-16 Score=133.49 Aligned_cols=167 Identities=27% Similarity=0.455 Sum_probs=107.5 Q ss_pred EEEEECCCC--CH----HHHHHHHHCCCCEEEECCCCHHHHHHCCCCEEEECCCCCC-CCCCCC---C-CHHHHHHHCCC Q ss_conf 999967964--10----2322222024541330465744644135788998588888-410112---1-10122210257 Q gi|254780420|r 208 VVCIDYGIR--SN----LLRVLSSLGCRITIVGAETSYKDIMSLQPDGVLLSNGPGD-PAVTSV---Y-SSPIICKLVDS 276 (396) Q Consensus 208 IvvIDfGiK--~n----Ilr~L~~~g~~v~Vvp~~~~~~~i~~~~pdgi~lSnGPGd-P~~~~~---~-~~~~~~~~~~~ 276 (396) T Consensus 1 i~viDYG~GNL~SlyrGV~~Al~~~G~~~~v~~~~--y~~~~--~aD~l~L-PGVG~F~~aM~~l~~~~~~~~~~~~~~~ 75 (211) T TIGR01855 1 IVVIDYGVGNLRSLYRGVKRALKRVGAEPVVVKDS--YKELE--KADKLIL-PGVGAFKAAMARLRELGLLDLLELVVKK 75 (211) T ss_pred CEEEECCCHHHHHHHHHHHHHHHHCCCEEEEECCC--CHHHH--CCCEEEE-CCCCCHHHHHHHHHHHHHHHHHHHHHHC T ss_conf 97874371656889999999998449817996286--03431--0686785-7858889999998850058788999961 Q ss_pred CCCEEEEECHHHHHHHHC---CC----------CCC---------CCCCCCCCCC--CCCEEC---CC-----CEEEEEC Q ss_conf 863478610058878752---85----------446---------6776752101--123477---89-----7099961 Q gi|254780420|r 277 GMPMFGICLGHQLLGLAL---GA----------QTV---------KMYQGHHGVN--HPVKNI---SN-----GTVEIVS 324 (396) Q Consensus 277 ~iPilGIClGhQ~l~~a~---G~----------~~~---------kl~~GhrG~N--~Pv~~~---~t-----~kv~iTs 324 (396) T Consensus 76 ~~P~lGiCLGMQLLfe~SeE~g~~~~GLG~i~G~V~k~~~~~~~~~lk~PHmGWN~v~~~~~~C~ll~g~~~~~~~YFV- 154 (211) T TIGR01855 76 KKPVLGICLGMQLLFERSEEGGGEVPGLGLIKGKVVKLEARVSLSKLKVPHMGWNEVEPVKESCPLLKGIDKGAYFYFV- 154 (211) T ss_pred CCCEEEEEHHHHHHHCCCCCCCCCCCCCEECCCEEEEECCCCCCCCCCCCCCCCCEEEEHHHCCCHHCCCCCCCCEEEE- T ss_conf 8968999802343001562437886653112761342056778872545756564231231155113077667815568- Q ss_pred CCCCEEEEHHHCCC-CCEEEEEECCCCEEEEEEECCCCEEEECCCCCCCCCCCCHHHHHHHHHHH Q ss_conf 45761570343699-82899998899808726867997789834878877670016899999999 Q gi|254780420|r 325 MNHGFAIDASSLPA-GLEETHISLFDSSNCGFRLIDQPVFSVQYHPESSPGPQDSYYLFSTFIDF 388 (396) Q Consensus 325 qNHg~~v~~~slp~-~~~v~~~~~nD~tiegi~~~~~~~~~vQfHPEa~PGP~D~~~~F~~F~~~ 388 (396) T Consensus 155 --HSY~~~~~~--~S~~v~a~~~YG~~F~AaV~--~~n~~G~QFHPEKS~--~~G~~lL~nf~~~ 211 (211) T TIGR01855 155 --HSYYAVCEE--ESEAVLAKADYGEKFTAAVQ--KDNIFGTQFHPEKSG--KTGLKLLKNFLEL 211 (211) T ss_pred --EEEEEECCC--CHHHEEEEHHCCCCEEEEEE--CCCEEEEEECCHHHH--HHHHHHHHHHHCC T ss_conf --866776168--81150112001863044665--487899972856888--8999999998529

HHsearch alignment for GI: 254780420 and conserved domain: TIGR01855