title: Chlorophyll biosynthesis: spotlight on protochlorophyllide reduction.
abstract: Photosynthetic organisms require chlorophyll or bacteriochlorophyll for their light trapping and energy transduction activities. The biosynthetic pathways of chlorophyll and bacteriochlorophyll are similar in most of their early steps, except for the reduction of protochlorophyllide (Pchlide) to chlorophyllide. Whereas angiosperms make use of a light-dependent enzyme, cyanobacteria, algae, bryophytes, pteridophytes and gymnosperms contain an additional, light-independent enzyme dubbed dark-operative Pchlide oxidoreductase (DPOR). Anoxygenic photosynthetic bacteria such as Rhodobacter capsulatus and Rhodobacter sphaeroides rely solely on DPOR. Recent atomic resolution of reductase and catalytic components of DPOR from R. sphaeroides and R. capsulatus, respectively, have revealed their similarity to nitrogenase components. In this review, we discuss the two fundamentally different mechanisms of Pchlide reduction in photosynthetic organisms.
authors.affiliation: Lehrstuhl für Pflanzenphysiologie, Universität Bayreuth, Universitätsstrasse 30, D-95447 Bayreuth, Germany. christiane.reinbothe@uni-bayreuth.de
authors.forename: Christiane
authors.initials: C
authors.lastname: Reinbothe
authors.forename: Majida
authors.initials: M
authors.lastname: El Bakkouri
authors.forename: Frank
authors.initials: F
authors.lastname: Buhr
authors.forename: Norifumi
authors.initials: N
authors.lastname: Muraki
authors.forename: Jiro
authors.initials: J
authors.lastname: Nomata
authors.forename: Genji
authors.initials: G
authors.lastname: Kurisu
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Fujita
authors.forename: Steffen
authors.initials: S
authors.lastname: Reinbothe
mesh_terms: D001419:Bacteria / Q000737:chemistry / Q000378:metabolism; D002734:Chlorophyll / Q000096:biosynthesis*; D056890:Eukaryota / Q000737:chemistry / Q000378:metabolism; D010788:Photosynthesis; D010944:Plants / Q000737:chemistry / Q000378:metabolism; D011521:Protochlorophyllide / Q000378:metabolism*
chemical_list: D002734:Chlorophyll; D011521:Protochlorophyllide