Chlorophyllide a reductase

{{short description|Enzyme}}

{{DISPLAYTITLE:Chlorophyllide a reductase}}

{{Infobox enzyme

| Name = Chlorophyllide a reductase

| EC_number = 1.3.7.15

| CAS_number =

| GO_code =

| image =

| width =

| caption =

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Chlorophyllide a reductase ({{EC number|1.3.7.15}}), also known as COR, is an enzyme with systematic name bacteriochlorophyllide-a:ferredoxin 7,8-oxidoreductase.{{cite journal |doi=10.1074/jbc.M113.546739|title=Chlorophyllide a Oxidoreductase Works as One of the Divinyl Reductases Specifically Involved in Bacteriochlorophyll a Biosynthesis|year=2014|last1=Harada|first1=Jiro|last2=Mizoguchi|first2=Tadashi|last3=Tsukatani|first3=Yusuke|last4=Yokono|first4=Makio|last5=Tanaka|first5=Ayumi|last6=Tamiaki|first6=Hitoshi|journal=Journal of Biological Chemistry|volume=289|issue=18|pages=12716–12726|pmid=24637023|pmc=4007461|doi-access=free}}{{cite journal |doi= 10.1038/srep09741|title= Rhodobacter sphaeroides mutants overexpressing chlorophyllide a oxidoreductase of Blastochloris viridis elucidate functions of enzymes in late bacteriochlorophyll biosynthetic pathways|year= 2015|last1= Tsukatani|first1= Yusuke|last2= Harada|first2= Jiro|last3= Nomata|first3= Jiro|last4= Yamamoto|first4= Haruki|last5= Fujita|first5= Yuichi|last6= Mizoguchi|first6= Tadashi|last7= Tamiaki|first7= Hitoshi|journal= Scientific Reports|volume= 5|page= 9741|pmid= 25978726|pmc= 4432870|bibcode= 2015NatSR...5E9741T}} It catalyses the following chemical reaction

:chlorophyllide a + 2 reduced ferredoxin + ATP + H₂O + 2 H⁺ $\backslash rightleftharpoons$ 3-deacetyl 3-vinylbacteriochlorophyllide a + 2 oxidized ferredoxin + ADP + phosphate

Chlorophyllide a.svg|Chlorophyllide a

Bacteriochlorophyllide a.png|Bacteriochlorophyllide a (R=H). The product of COR retains the vinyl group of the substrate in place of the acetyl group shown

This reduction (with trans stereochemistry) of the pyrrole ring B gives the characteristic 18-electron aromatic system that distinguishes bacteriochlorophylls from chlorophylls, which retain the chlorin system of chlorophyllide a.

This enzyme is present in purple bacteria such as Rhodobacter capsulatus and Rhodobacter sphaeroides, and Pseudomonadota. It is a component of the biosynthetic pathway to bacteriochlorophylls.{{cite web |url=https://biocyc.org/META/NEW-IMAGE?type=PATHWAY&object=PWY-5526 |title=Pathway: bacteriochlorophyll a biosynthesis |author=R. Caspi |publisher=MetaCyc Metabolic Pathway Database |date=2015-12-08 |accessdate=2020-06-04 }}{{cite journal | vauthors = Willows RD | title = Biosynthesis of chlorophylls from protoporphyrin IX | journal = Natural Product Reports | volume = 20 | issue = 3 | pages = 327–41 | date = June 2003 | pmid = 12828371 | doi = 10.1039/B110549N }}{{cite journal | vauthors = Bollivar DW | title = Recent advances in chlorophyll biosynthesis | journal = Photosynthesis Research | volume = 90 | issue = 2 | pages = 173–94 | date = November 2006 | pmid = 17370354 | doi = 10.1007/s11120-006-9076-6 | s2cid = 23808539 }}