1OOW

The crystal structure of the spinach plastocyanin double mutant G8D/L12E gives insight into its low reactivity towards photosystem 1 and cytochrome f

Summary for 1OOW

• Entry DOI: 10.2210/pdb1oow/pdb
• Descriptor: Plastocyanin, chloroplast, COPPER (II) ION (3 entities in total)
• Functional Keywords: cupredoxin, beta sandwich, electron transport, membrane
• Biological source: Spinacia oleracea (spinach)
• Total number of polymer chains: 1
• Total formula weight: 10558.10

Authors

Jansson, H.,Okvist, M.,Jacobson, F.,Ejdeback, M.,Hansson, O.,Sjolin, L. (deposition date: 2003-03-04, release date: 2004-02-17, Last modification date: 2023-08-16)

Primary citation

Jansson, H.,Okvist, M.,Jacobson, F.,Ejdeback, M.,Hansson, O.,Sjolin, L.
The crystal structure of the spinach plastocyanin double mutant G8D/L12E gives insight into its low reactivity towards photosystem 1 and cytochrome f.
Biochim.Biophys.Acta, 1607:203-210, 2003

PubMed Abstract: Plastocyanin (Pc) is a copper-containing protein, which functions as an electron carrier between the cytochrome b(6)f and photosystem 1 (PS1) complexes in the photosynthetic electron transfer (ET) chain. The ET is mediated by His87 situated in the hydrophobic surface in the north region of Pc. Also situated in this region is Leu12, which mutated to other amino acids severely disturbs the ET from cytochrome f and to PS1, indicating the importance of the hydrophobic surface. The crystal structure of the Pc double mutant G8D/L12E has been determined to 2.0 A resolution, with a crystallographic R-factor of 18.3% (R(free)=23.2%). A comparison with the wild-type structure reveals that structural differences are limited to the sites of the mutations. In particular, there is a small but significant change in the hydrophobic surface close to His87. Evidently, this leads to a mismatch in the reactive complex with the redox partners. For PS1 this results in a 20 times weaker binding and an eightfold slower ET as determined by kinetic measurements. The mutations that have been introduced do not affect the optical absorption spectrum. However, there is a small change in the EPR spectrum, which can be related to changes in the copper coordination geometry.

PubMed: 14670610
DOI: 10.1016/j.bbabio.2003.09.011

Experimental method

X-RAY DIFFRACTION (2 Å)