Tethering of ferredoxin:NADP+ oxidoreductase to thylakoid membranes is mediated by novel chloroplast protein TROL.
Working in tandem, two photosystems in the chloroplast thylakoid membranes produce a linear electron flow from H(2)O to NADP(+). Final electron transfer from ferredoxin to NADP(+) is accomplished by a flavoenzyme ferredoxin:NADP(+) oxidoreductase (FNR). Here we describe TROL (thylakoid rhodanese-like protein), a nuclear-encoded component of thylakoid membranes that is required for tethering of FNR and sustaining efficient linear electron flow (LEF) in vascular plants. TROL consists of two distinct modules; a centrally positioned rhodanese-like domain and a C-terminal hydrophobic FNR binding region. Analysis of Arabidopsis mutant lines indicates that, in the absence of TROL, relative electron transport rates at high-light intensities are severely lowered accompanied with significant increase in non-photochemical quenching (NPQ). Thus, TROL might represent a missing thylakoid membrane docking site for a complex between FNR, ferredoxin and NADP(+). Such association might be necessary for maintaining photosynthetic redox poise and enhancement of the NPQ.
Jurić
Snjezana
S
Department of Molecular Biology, Ruder Bosković Institute, Bijenicka cesta 54, HR-10000 Zagreb, Croatia.
Hazler-Pilepić
Kroata
K
Tomasić
Ana
A
Lepedus
Hrvoje
H
Jelicić
Branka
B
Puthiyaveetil
Sujith
S
Bionda
Tihana
T
Vojta
Lea
L
Allen
John F
JF
Schleiff
Enrico
E
Fulgosi
Hrvoje
H
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D002736:Chloroplasts / Q000378:metabolism / Q000648:ultrastructure; D004579:Electron Transport / Q000502:physiology; D005287:Ferredoxin-NADP Reductase / Q000378:metabolism*; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D008969:Molecular Sequence Data; D018515:Plant Leaves / Q000033:anatomy & histology / Q000235:genetics / Q000378:metabolism; D017434:Protein Structure, Tertiary; D021381:Protein Transport / Q000502:physiology; D016415:Sequence Alignment; D015398:Signal Transduction; D020524:Thylakoids / Q000378:metabolism*
D029681:Arabidopsis Proteins; D008565:Membrane Proteins; C547211:TROL protein, Arabidopsis; D005287:Ferredoxin-NADP Reductase