AC   MF_00353;
DC   Protein; auto
TR   HAMAP; MF_00353; -; 1; level=0
XX
Names: ChlB_BchB
XX
case <OC:Bacteria> and not <OC:Cyanobacteriota>
ID   BCHB
end case
case <OC:Cyanobacteriota> or <OG:Chloroplast>
ID   CHLB
end case
DE   RecName: Full=Light-independent protochlorophyllide reductase subunit B;
DE            Short=DPOR subunit B;
DE            Short=LI-POR subunit B;
DE            EC=1.3.7.7;
case <OC:Bacteria> and not <OC:Cyanobacteriota>
GN   Name=bchB;
end case
case <OC:Cyanobacteriota> or <OG:Chloroplast>
GN   Name=chlB;
end case
XX
case <OC:Bacteria> and not <OC:Cyanobacteriota>
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 (BchN-BchB) is the
CC       catalytic component of the complex.
CC   -!- PATHWAY: Porphyrin-containing compound metabolism; bacteriochlorophyll
CC       biosynthesis (light-independent).
CC   -!- SUBUNIT: Protochlorophyllide reductase is composed of three subunits;
CC       BchL, BchN and BchB. Forms a heterotetramer of two BchB and two BchN
CC       subunits.
end case
case <OC:Cyanobacteriota> or <OG:Chloroplast>
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.
CC   -!- PATHWAY: Porphyrin-containing compound metabolism; chlorophyll
CC       biosynthesis (light-independent).
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.
end case
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   -!- COFACTOR:
CC       Name=[4Fe-4S] cluster; Xref=ChEBI:CHEBI:49883;
CC       Note=Binds 1 [4Fe-4S] cluster per heterodimer. The cluster is bound at
CC       the heterodimer interface by residues from both subunits.;
case <OG:Chloroplast>
CC   -!- SUBCELLULAR LOCATION: Plastid, chloroplast.
end case
CC   -!- SIMILARITY: Belongs to the ChlB/BchB/BchZ family.
XX
DR   Pfam; PF00148; Oxidored_nitro; 1; trigger=no
DR   Pfam; PF08369; PCP_red; 1; trigger=no
DR   PIRSF; PIRSF000163; PCP_ChlB; 1; trigger=no
DR   NCBIfam; TIGR01278; DPOR_BchB; 1; trigger=no
XX
KW   ATP-binding
KW   Chlorophyll biosynthesis
case <OC:Bacteria> and not <OC:Cyanobacteriota>
KW   Bacteriochlorophyll biosynthesis
end case
KW   4Fe-4S
KW   Iron
KW   Iron-sulfur
KW   Metal-binding
KW   Nucleotide-binding
KW   Oxidoreductase
KW   Photosynthesis
XX
GO   GO:0005524; F:ATP binding
GO   GO:0016636; F:oxidoreductase activity, acting on the CH-CH group of donors, iron-sulfur protein as acceptor
GO   GO:0051539; F:4 iron, 4 sulfur cluster binding
case <OC:Bacteria> and not <OC:Cyanobacteriota>
GO   GO:0030494; P:bacteriochlorophyll biosynthetic process
end case
case <OC:Cyanobacteriota> or <OG:Chloroplast>
GO   GO:0015995; P:chlorophyll biosynthetic process
end case
GO   GO:0015979; P:photosynthesis
case <OG:Chloroplast>
GO   GO:0009507; C:chloroplast
end case
XX
FT   From: BCHB_RHOCB (P26163)
FT   BINDING         409..410
FT                   /ligand="substrate"
FT   Condition: G-[LM]
FT   ACT_SITE        274
FT                   /note="Proton donor"
FT   Condition: D
FT   BINDING         36
FT                   /ligand="[4Fe-4S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:49883"
FT                   /ligand_note="ligand shared with heterodimeric
FT                   partner"
FT   Condition: D
XX
Size: 440-568;
Related: None;
Template: P26163; P95463;
Scope:
 Bacteria
 Plastid
Fusion:
 Nter: None
 Cter: None
Duplicate: None
Plasmid: None
Comments: External expert: Yuichi Fujita, fujita@protein.osaka-u.ac.jp.
 Divergent chlamydomonadaceae (with insert) not shown in alignment and not
 used in size range.
XX
# Revision 1.46 2023/06/01
//