>cd00642 GTP_cyclohydro1 GTP cyclohydrolase I (GTP-CH-I) catalyzes the conversion of GTP into dihydroneopterin triphosphate. The enzyme product is the precursor of tetrahydrofolate in eubacteria, fungi, and plants and of the folate analogs in methanogenic bacteria. In vertebrates and insects it is the biosynthtic precursor of tetrahydrobiopterin (BH4) which is involved in the formation of catacholamines, nitric oxide, and the stimulation of T lymphocytes. The biosynthetic reaction of BH4 is controlled by a regulatory protein GFRP which mediates feedback inhibition of GTP-CH-I by BH4. This inhibition is reversed by phenylalanine. The decameric GTP-CH-I forms a complex with two pentameric GFRP in the presence of phenylalanine or a combination of GTP and BH4, respectively.

Probab=100.00 E-value=0 Score=518.21 Aligned_cols=184 Identities=49% Similarity=0.864 Sum_probs=174.3 Q ss_pred CHHHHHHHHHHHHHHHCCCCCCHHHCCCHHHHHHHHHHHHHHCCCCCHHHHHHHHCCCCCCCCCCEEEECCEEEEEECCC Q ss_conf 48999999999999814788881001126789999999997608653123443202566556676289618058772110 Q gi|255764506|r 17 TVEEAKEAIRVILRWIGDDPDREGLKDTPDRVIKSYKELFAGYKQIPTTQDTSRFHFGEASKYQDMVLIKDISFFSYCEH 96 (205) Q Consensus 17 ~~~~i~~av~~lL~~LGeDp~regL~~TP~Rvak~~~e~~~Gy~~~~~~~~~~~~~~~~~~~~~~mVvv~~I~f~S~CEH 96 (205) T Consensus 2 ~i~~ie~av~~iL~~lGeD~~r~gL~~TP~Rvak~~~e~~~G~~~~~~~~~~~~~~---~~~~~~~V~~~~I~f~S~CEH 78 (185) T cd00642 2 RLEKIAAAVREILELLGEDPNREGLLETPERVAKAYQEITSGYDQALNDPKNTAIF---DEDHDEMVIVKDITLFSMCEH 78 (185) T ss_pred HHHHHHHHHHHHHHHHCCCCCCCHHHHCHHHHHHHHHHHHHCCCCCCHHHHCCCCC---CCCCCEEEEEECCCEEEECCC T ss_conf 58999999999999967999950013579999999999973717892055316676---778871799918247884255 Q ss_pred CEEEEEEEEEEEEECCCCCCCHHHHHHHHHHHHCCCCCHHHHHHHHHHHHHHHCCCCCEEEEEEEEEEEEEECCCCCCCC Q ss_conf 02346557899996388543467799999998315426689999999999973273847999994884252238355998 Q gi|255764506|r 97 HILPIWGKIHLAYIPKKHVIGLSKLVRILEVYSRRLQIQERLTMQIAHAIESSTDSKGVAVLIEGQHMCMSMRGIKRDGL 176 (205) Q Consensus 97 HllPf~G~~~IaYiP~~~viGlSKl~Riv~~~a~RlQ~QErlT~qIa~~l~~~l~~~gv~V~i~A~H~Cm~~RGv~~~~s 176 (205) T Consensus 79 HllPf~G~~~VaYiP~~~viGLSKl~RiV~~~arRlQvQErlT~qIa~~l~~~l~~~gV~V~ieA~H~Cm~~RGv~~~~s 158 (185) T cd00642 79 HLVPFYGKVHIAYIPKDKVIGLSKLARIVEFFSRRLQVQERLTKQIAVAIQEILGPQGVAVVIEATHMCMVMRGVRKPGS 158 (185) T ss_pred CCCCEEEEEEEEEECCCCCCCHHHHHHHHHHHHCCCHHHHHHHHHHHHHHHHHCCCCCEEEEEEEEEEEECCCCCCCCCC T ss_conf 66616668999997688504389999999999648689989999999999984098978999998983176618889997 Q ss_pred EEEEEEEEEEECCCHHHHHHHHHHHCC Q ss_conf 599967774430688999999998326 Q gi|255764506|r 177 TTVTTAFTGEFSRDKGKTDFFLKMTHN 203 (205) Q Consensus 177 ~~~T~~~~G~F~~d~~~r~ef~~li~~ 203 (205) T Consensus 159 ~t~T~~~~G~F~~d~~~R~Efl~~i~~ 185 (185) T cd00642 159 KTVTSAMLGVFKEDPKTREEFLRLIRK 185 (185) T ss_pred EEEEEEEEEEECCCHHHHHHHHHHHCC T ss_conf 399988788947898999999997459

HHsearch alignment for GI: 255764506 and conserved domain: cd00642