>cd02810 DHOD_DHPD_FMN Dihydroorotate dehydrogenase (DHOD) and Dihydropyrimidine dehydrogenase (DHPD) FMN-binding domain. DHOD catalyzes the oxidation of (S)-dihydroorotate to orotate. This is the fourth step and the only redox reaction in the de novo biosynthesis of UMP, the precursor of all pyrimidine nucleotides. DHOD requires FMN as co-factor. DHOD divides into class 1 and class 2 based on their amino acid sequences and cellular location. Members of class 1 are cytosolic enzymes and multimers while class 2 enzymes are membrane associated and monomeric. The class 1 enzymes can be further divided into subtypes 1A and 1B which are homodimers and heterotetrameric proteins, respectively. DHPD catalyzes the first step in pyrimidine degradation: the NADPH-dependent reduction of uracil and thymine to the corresponding 5,6-dihydropyrimidines. DHPD contains two FAD, two FMN and eight [4Fe-4S] clusters, arranged in two electron transfer chains that pass its homodimeric interface twice. Two of

Probab=98.33 E-value=4.4e-06 Score=63.04 Aligned_cols=137 Identities=20% Similarity=0.262 Sum_probs=86.3 Q ss_pred CCHHHHHHHHHHHCCCCEEEEECC--C---C----H-HHHHHHHHHHHHHHCCCCCEE---CCCCCC---HHHHHHHHHC Q ss_conf 701567899987313666998248--4---1----1-388999999999857987245---146469---9999999854 Q gi|254780889|r 231 AKDIADRVGPLFDVNVDLVVVDTA--H---G----H-SQKVLDAVVQIKKNFPSLLVM---AGNIAT---AEGALALIDA 294 (493) Q Consensus 231 ~~d~~eRa~~LveaGvDviviD~a--h---G----h-~~~~~~~i~~~k~~~~~~~ii---~GNv~t---~~~~~~l~~~ 294 (493) T Consensus 110 ~~~~~~~a~~~~~~gad~lElNiScPn~~~~~~~~~~~~~~~~i~~~v~~~~-~~Pv~vKLsp~~~~~~~~~ia~~~~~~ 188 (289) T cd02810 110 KEDYVELARKIERAGAKALELNLSCPNVGGGRQLGQDPEAVANLLKAVKAAV-DIPLLVKLSPYFDLEDIVELAKAAERA 188 (289) T ss_pred HHHHHHHHHHHHHHCCCEEEEEEECCCCCCCCCCCCCHHHHHHHHHHHHHCC-CCCEEEECCCCCCHHHHHHHHHHHHHC T ss_conf 7899999999998479848998403675655320149999999999998602-687488427887616899999999975 Q ss_pred CCCEEEEEE--CCCCCCCCC--HH-----CCC-CCCCCH-HHHHHHHHHHC--CCCEEEEECCCCCHHHHEEEEEECCCE Q ss_conf 875899610--278766531--00-----015-743100-37889998622--698199726543777621336714878 Q gi|254780889|r 295 GADIIKVGI--GPGSICTTR--VV-----TGV-GCPQLS-AIMSVVEVAER--AGVAIVADGGIRFSGDIAKAIAAGSAC 361 (493) Q Consensus 295 Gad~ikvGi--g~Gs~CtTr--~~-----~g~-g~pq~~-av~~~~~~~~~--~~~~iiadGGi~~~gdi~kAla~GA~~ 361 (493) T Consensus 189 ga~gv~~~Nt~~~~~~~~~~~~~~~~~~~gGlSG~~i~~~al~~v~~~~~~~~~~i~Iig~GGI~~~~da~e~i~aGA~~ 268 (289) T cd02810 189 GADGLTAINTISGRVVDLKTVGPGPKRGTGGLSGAPIRPLALRWVARLAARLQLDIPIIGVGGIDSGEDVLEMLMAGASA 268 (289) T ss_pred CCCEEEEECCCCCCCCCCCCCCCCCCCCCCCCCCHHHHHHHHHHHHHHHHHCCCCCEEEEECCCCCHHHHHHHHHCCCCH T ss_conf 99689996787765554444554456776523662778899999999999749996099989939999999999849979 Q ss_pred EEECCHH Q ss_conf 9932301 Q gi|254780889|r 362 VMIGSLL 368 (493) Q Consensus 362 VM~G~~~ 368 (493) T Consensus 269 Vqv~Tal 275 (289) T cd02810 269 VQVATAL 275 (289) T ss_pred HHHHHHH T ss_conf 9998999

HHsearch alignment for GI: 254780889 and conserved domain: cd02810