ID   CHLB_PROMA              Reviewed;         530 AA.
AC   Q7VD38;
DT   15-JAN-2008, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-2003, sequence version 1.
DT   27-MAR-2024, entry version 102.
DE   RecName: Full=Light-independent protochlorophyllide reductase subunit B {ECO:0000255|HAMAP-Rule:MF_00353};
DE            Short=DPOR subunit B {ECO:0000255|HAMAP-Rule:MF_00353};
DE            Short=LI-POR subunit B {ECO:0000255|HAMAP-Rule:MF_00353};
DE            EC=1.3.7.7 {ECO:0000255|HAMAP-Rule:MF_00353};
GN   Name=chlB {ECO:0000255|HAMAP-Rule:MF_00353};
GN   OrderedLocusNames=Pro_0545;
OS   Prochlorococcus marinus (strain SARG / CCMP1375 / SS120).
OC   Bacteria; Cyanobacteriota; Cyanophyceae; Synechococcales;
OC   Prochlorococcaceae; Prochlorococcus.
OX   NCBI_TaxID=167539;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=SARG / CCMP1375 / SS120;
RX   PubMed=12917486; DOI=10.1073/pnas.1733211100;
RA   Dufresne A., Salanoubat M., Partensky F., Artiguenave F., Axmann I.M.,
RA   Barbe V., Duprat S., Galperin M.Y., Koonin E.V., Le Gall F., Makarova K.S.,
RA   Ostrowski M., Oztas S., Robert C., Rogozin I.B., Scanlan D.J.,
RA   Tandeau de Marsac N., Weissenbach J., Wincker P., Wolf Y.I., Hess W.R.;
RT   "Genome sequence of the cyanobacterium Prochlorococcus marinus SS120, a
RT   nearly minimal oxyphototrophic genome.";
RL   Proc. Natl. Acad. Sci. U.S.A. 100:10020-10025(2003).
CC   -!- FUNCTION: Component of the dark-operative protochlorophyllide reductase
CC       (DPOR) that uses Mg-ATP and reduced ferredoxin to reduce ring D of
CC       protochlorophyllide (Pchlide) to form chlorophyllide a (Chlide). This
CC       reaction is light-independent. The NB-protein (ChlN-ChlB) is the
CC       catalytic component of the complex. {ECO:0000255|HAMAP-Rule:MF_00353}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=2 ADP + chlorophyllide a + oxidized 2[4Fe-4S]-[ferredoxin] + 2
CC         phosphate = 2 ATP + 2 H2O + protochlorophyllide a + reduced 2[4Fe-
CC         4S]-[ferredoxin]; Xref=Rhea:RHEA:28202, Rhea:RHEA-COMP:10002,
CC         Rhea:RHEA-COMP:10004, ChEBI:CHEBI:15377, ChEBI:CHEBI:30616,
CC         ChEBI:CHEBI:33722, ChEBI:CHEBI:33723, ChEBI:CHEBI:43474,
CC         ChEBI:CHEBI:83348, ChEBI:CHEBI:83350, ChEBI:CHEBI:456216; EC=1.3.7.7;
CC         Evidence={ECO:0000255|HAMAP-Rule:MF_00353};
CC   -!- COFACTOR:
CC       Name=[4Fe-4S] cluster; Xref=ChEBI:CHEBI:49883;
CC         Evidence={ECO:0000255|HAMAP-Rule:MF_00353};
CC       Note=Binds 1 [4Fe-4S] cluster per heterodimer. The cluster is bound at
CC       the heterodimer interface by residues from both subunits.
CC       {ECO:0000255|HAMAP-Rule:MF_00353};
CC   -!- PATHWAY: Porphyrin-containing compound metabolism; chlorophyll
CC       biosynthesis (light-independent). {ECO:0000255|HAMAP-Rule:MF_00353}.
CC   -!- SUBUNIT: Protochlorophyllide reductase is composed of three subunits;
CC       ChlL, ChlN and ChlB. Forms a heterotetramer of two ChlB and two ChlN
CC       subunits. {ECO:0000255|HAMAP-Rule:MF_00353}.
CC   -!- SIMILARITY: Belongs to the ChlB/BchB/BchZ family. {ECO:0000255|HAMAP-
CC       Rule:MF_00353}.
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DR   EMBL; AE017126; AAP99590.1; -; Genomic_DNA.
DR   RefSeq; NP_874938.1; NC_005042.1.
DR   RefSeq; WP_011124699.1; NC_005042.1.
DR   PDB; 2YNM; X-ray; 2.10 A; D=1-530.
DR   PDBsum; 2YNM; -.
DR   AlphaFoldDB; Q7VD38; -.
DR   SMR; Q7VD38; -.
DR   IntAct; Q7VD38; 2.
DR   STRING; 167539.Pro_0545; -.
DR   EnsemblBacteria; AAP99590; AAP99590; Pro_0545.
DR   KEGG; pma:Pro_0545; -.
DR   PATRIC; fig|167539.5.peg.560; -.
DR   eggNOG; COG2710; Bacteria.
DR   HOGENOM; CLU_025470_0_0_3; -.
DR   OrthoDB; 5717231at2; -.
DR   UniPathway; UPA00670; -.
DR   Proteomes; UP000001420; Chromosome.
DR   GO; GO:0051539; F:4 iron, 4 sulfur cluster binding; IEA:UniProtKB-UniRule.
DR   GO; GO:0005524; F:ATP binding; IEA:UniProtKB-UniRule.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   GO; GO:0016730; F:oxidoreductase activity, acting on iron-sulfur proteins as donors; IEA:InterPro.
DR   GO; GO:0016636; F:oxidoreductase activity, acting on the CH-CH group of donors, iron-sulfur protein as acceptor; IEA:UniProtKB-UniRule.
DR   GO; GO:0036068; P:light-independent chlorophyll biosynthetic process; IEA:UniProtKB-UniPathway.
DR   GO; GO:0019685; P:photosynthesis, dark reaction; IEA:InterPro.
DR   CDD; cd01981; Pchlide_reductase_B; 1.
DR   Gene3D; 1.20.89.20; -; 1.
DR   Gene3D; 3.40.50.1980; Nitrogenase molybdenum iron protein domain; 3.
DR   Gene3D; 1.10.8.550; Proto-chlorophyllide reductase 57 kD subunit B; 1.
DR   HAMAP; MF_00353; ChlB_BchB; 1.
DR   InterPro; IPR013580; LI-POR_suB-like_C.
DR   InterPro; IPR000510; Nase/OxRdtase_comp1.
DR   InterPro; IPR042298; P-CP_red_C.
DR   InterPro; IPR005969; Protochl_reductB.
DR   InterPro; IPR016209; Protochlorophyllide_Rdtase.
DR   NCBIfam; TIGR01278; DPOR_BchB; 1.
DR   PANTHER; PTHR33712; LIGHT-INDEPENDENT PROTOCHLOROPHYLLIDE REDUCTASE SUBUNIT B; 1.
DR   PANTHER; PTHR33712:SF7; LIGHT-INDEPENDENT PROTOCHLOROPHYLLIDE REDUCTASE SUBUNIT B; 1.
DR   Pfam; PF00148; Oxidored_nitro; 1.
DR   Pfam; PF08369; PCP_red; 1.
DR   PIRSF; PIRSF000163; PCP_ChlB; 1.
DR   SUPFAM; SSF53807; Helical backbone' metal receptor; 1.
PE   1: Evidence at protein level;
KW   3D-structure; 4Fe-4S; ATP-binding; Chlorophyll biosynthesis; Iron;
KW   Iron-sulfur; Metal-binding; Nucleotide-binding; Oxidoreductase;
KW   Photosynthesis; Reference proteome.
FT   CHAIN           1..530
FT                   /note="Light-independent protochlorophyllide reductase
FT                   subunit B"
FT                   /id="PRO_1000048411"
FT   REGION          448..483
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   COMPBIAS        455..480
FT                   /note="Polar residues"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   ACT_SITE        290
FT                   /note="Proton donor"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00353"
FT   BINDING         36
FT                   /ligand="[4Fe-4S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:49883"
FT                   /ligand_note="ligand shared with heterodimeric partner"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00353"
FT   BINDING         425..426
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00353"
FT   STRAND          2..6
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   HELIX           12..22
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   STRAND          23..31
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   HELIX           36..39
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   HELIX           40..44
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   STRAND          54..57
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   HELIX           62..66
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   HELIX           69..84
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   STRAND          87..93
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   HELIX           95..100
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   HELIX           104..108
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   TURN            109..112
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   STRAND          117..119
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   TURN            124..126
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   HELIX           129..145
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   HELIX           159..163
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   STRAND          168..172
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   STRAND          178..180
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   HELIX           181..194
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   STRAND          198..204
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   HELIX           209..212
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   HELIX           213..217
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   STRAND          218..224
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   HELIX           226..240
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   HELIX           252..266
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   HELIX           277..279
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   HELIX           282..287
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   HELIX           289..294
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   STRAND          298..301
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   HELIX           305..317
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   STRAND          322..329
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   HELIX           331..333
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   HELIX           334..343
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   HELIX           354..364
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   STRAND          367..371
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   HELIX           373..382
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   STRAND          386..388
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   STRAND          390..392
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   HELIX           395..397
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   HELIX           407..419
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   HELIX           425..433
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   STRAND          438..440
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   HELIX           446..448
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   HELIX           483..490
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   HELIX           494..496
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   HELIX           497..510
FT                   /evidence="ECO:0007829|PDB:2YNM"
FT   HELIX           518..527
FT                   /evidence="ECO:0007829|PDB:2YNM"
SQ   SEQUENCE   530 AA;  58729 MW;  7D5A10C8B8D0FF2E CRC64;
     MELTLWTYEG PPHIGAMRIA TSMKGLHYVL HAPQGDTYAD LLFTMIERRG SRPPVTYTTF
     QARDLGGDTA ELVKGHIFEA VERFKPEALL VGESCTAELI QDQPGSLAKG MGLNIPIVSL
     ELPAYSKKEN WGASETFYQL IRGLLKEISE DSSNNAKQSW QEEGRRPRVN LLGPSLLGFR
     CRDDVLEIQK ILGENGIDIN VIAPLGASPS DLMRLPKADA NVCLYPEIAE STCLWLERNF
     KTPFTKVVPI GVKATQDFLE ELYELLGMEV SNSISNSDQS KLPWYSKSVD SNYLTGKRVF
     IFGDGTHVLA AARIANEELG FEVVGIGTYS REMARKVRAA ATELGLEALI TNDYLEVEES
     IKECAPELVL GTQMERHSAK RLGIPCAVIS TPMHVQDVPA RYSPQMGWEG ANVIFDDWVH
     PLMMGLEEHL IGMFRHDFEF TDGHQSHLGH LGGHASETKT SSKGINQSPN NHSPAGESIH
     WTSEGESELA KIPFFVRGKV RRNTEKYARQ AGCREIDGET LLDAKAHFGA
//