Since the determination of the structure of poplar plastocyanin in 1978. The copper atom has a highly distorted tetrahedral. Molecular dynamics simulation and essential dynamics study of mutated plastocyanin. Kinetics of electron transfer between plastocyanin and the. Two homologous plastocyanin isoforms are encoded by the genes pete1 and pete2 in the nuclear genome of arabidopsis thaliana. The results suggest that the coppercysteine sulfur bond length in the crystal structure of plastocyanin is too short and should be closer to the corresponding bond lengths in related blue copper. Plastocyanin pc from filamentous strains is usually positively charged at ph 7, whereas the isoelectric. Paper open access theoretical studies on association.
Plastocyanin is a 10 kd blue copper protein which is located in the lumen of the thylakoid where it functions as a mobileelectron carrier shuttling electrons from cytochromef to p700 in photosystem. The current structure represents the oxidized plastocyanin, copper ii, at low ph approximately 4. The energy term for all distance restraints etot is shown as a function of the cycle number. Visiting professor, structural genomics consortium, university of oxford, 202014. Immunoblots and mass spectrometric analysis of proteolytic peptides indicate that the two negative patches conserved in plant plastocyanins are crosslinked with lysine residues of a domain near the nterminus of the psaf subunit of photosystem i. Get 50% off quizlet plus through monday learn more. A comparative structural and functional analysis of. Modelling the spectroscopy and dynamics of plastocyanin. Structural analysis of the reducing side of photosystem i psi has been carried out using chemical cross. Plastocyanin is a coppercontaining protein that mediates electrontransfer. These molecules are visualized, downloaded, and analyzed by users who range from students to specialized scientists.
Structural and functional analysis of the reducing side of. Mutants, overexpressors, and interactors of arabidopsis. Structural dynamics in the plastocyaninphotosystem 1 electrontransfer complex as revealed by mutant studies. Molinaheredia, alexis balme, manuel hervas, jose a. In addition to standard metrics of alignment quality e. Pdf plastocyanin and cytochrome c 6 are two soluble metalloproteins that act as alternative electron carriers between the membraneembedded complexes. A detailed analysis of the root mean square fluctuations, hbonding pattern and dynamical crosscorrelation map has been performed. Moreover, phenotypic analysis of atc61 pete1 and atc61 pete2 double mutants, each lacking cyt c6a and one of. Conversion of these negative to uncharged patches of plastocyanin by sitedirected mutation d42n. Null mutations in the pete genes resulted in plants, designated pete1 and pete2, with decreased plastocyanin contents. Users can perform simple and advanced searches based on annotations relating to sequence, structure and function. The calculated excitation energies were too high, although analysis showed the ligand. Modular origins of biological electron transfer chains.
Despite plastocyanin and cytochrome c 6 differing in the nature of their redox center one is a copper protein, the other is a heme protein and folding pattern one is a. Cytochrome c 6 does contain two functional areas that are equivalent to those previously described in plastocyanin. Computational approaches to structural and functional analysis of plastocyanin and other blue copper proteins. Academic leadership fellow, unc institute for the arts and humanities, 20102011. The crystal structure of amicyanin, a cupredoxin isolated from paracoccus denitrificans, has been determined by molecular replacement. Roberts va, freeman hc, olson aj, tainer ja, getzoff ed. At the molecular level, the function of plastocyanin. It is too soon to translate the above summary into structural terms. Computational simulation and analysis of dynamic association. Plastocyanin is a small, acidic, blue copper protein found in most oxygenic phototrophs. Computational approaches to structural and functional. In the latter, the copper protein plastocyanin acts as a soluble 33 carrier transferring electrons between the two membraneembedded complexes cytochromeb 6f 34 and photosystem i.
By use of the recently developed expression system hibino et al. The cytochrome faplastocyanin complex as a model to study. Q mmm optimization of the structure of the active site and its surroundings using the bp86 functional and splitvalence. The first is as fiducial markers of the quality of protein structure alignments 18. Plastocyanin definition of plastocyanin by merriamwebster. The structure of p700 has also been analyzed by xray analysis 6, 7. Plastocyanin is a 10 kd blue copper protein which is located in the lumen of the thylakoid where it functions as a mobileelectron carrier shuttling electrons from. A comparative structural and functional analysis of cytochrome c m, cytochrome c 6 and plastocyanin from the cyanobacterium synechocystis sp. Functional analysis of photosystem i complex by site. Functional characterization of the small regulatory subunit. Pdb 1aac structure summary protein data bank in europe.
Molecular dynamics simulation and essential dynamics study of. A comparative structural and functional analysis of cytochrome cm, cytochrome c6 and plastocyanin from the cyanobacterium synechocystis sp. The electrostatic interaction between plastocyanin pc and cytochrome f cyt f, electron transfer partners in photosynthesis was studied using brownian dynamics bd simulations. Incubation of psi isolated from barley hordeum vulgare l. Request pdf computational approaches to structural and functional analysis of plastocyanin and other blue copper proteins computational techniques are becoming increasingly important in. The protein is a prototype of the blue copper proteins, a family of intensely bluecolored metalloproteins. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Like plastocyanin from other species, it is an antiparallel. The dansyledman procedure showed that plastocyanin has only the one nh 2 terminal sequence, leuglxvalleu, and reduction and carboxymethylation of the apoprotein gave a homogeneous product, as judged by acrylamide gel electrophoresis and. It is found in a variety of plants, where it participates in photosynthesis. Electrostatic orientation of the electrontransfer complex between plastocyanin and cytochrome c. As a member of the wwpdb, the rcsb pdb curates and annotates pdb data according to agreed upon standards. Plastocyanin definition is a coppercontaining protein that acts as an intermediary in photosynthetic electron transport. A representative restrained rigidbody molecular dynamics run.
Amino acid analysis indicated that the minimum molecular weight of the polypeptide chain is 10,626. To investigate the role of the copperligand met92 in the structural and functional properties of silene plastocyanin pc, met92 was replaced with gin, which is the purposed fourth copperligand in another blue copper protein, stellacyanin. Plastocyanin and cytochrome c 6 are two soluble metalloproteins that act as alternative electron carriers between the membraneembedded complexes cytochromes b 6 f and photosystem i. Structural basis of efficient electron transport between. Plastocyanin is a small 97104 amino acids copperbinding protein whose function in oxygenic photsynthesis is the catalysis of electron transfer from cytochrome. Photosystem i, one of the two light driven reaction centers of oxygenic photosynthesis, functions as the lightdriven plastocyanin ferredoxin oxidoreductase in the thylakoid membranes of cyanobacteria and chloroplasts.
Brownian dynamics study of the interaction between. The analysis of the simulation stability has revealed that the mutant maintains its globular shape and is almost stable during all the simulation run. By using the software package macrodox, which implements the bd algorithm of northrup et al. Redinbo mr, cascio d, choukair mk, rice d, merchant s, yeates to. Xray crystal structure analysis of plastocyanin at 2. Crystal structure analysis of amicyanin and apoamicyanin from. Plastocyanin is one of the best characterized of the photosynthetic electron transfer proteins. Natural resistance to inhibitors of the ubiquinol cytochrome. Proteinprotein interactions in plastocyanin function. It has been proposed previously that cytochrome cm can replace cytochrome c6 and plastocyanin in transferring electrons between the two membrane.
The cyt bc complex was found to be made up of at least three subunits. Cytochrome cm is a new cclass photosynthetic haem protein whose physiological role is still unknown. The threedimensional structure of plastocyanin, a blue or type 1 copperprotein, has been determined at a resolution of 2. Structural and functional similarities have been reported for both types of cyt bc 3, 9, 41. Aa,31 and crystal structure analysis of plastocyanin from a wide range of. Md simulation has proved to be a useful tool to investigate the structural, dynamical and functional effects of the introduction of a nonnative disulfide bridge at the plastocyanin surface. In the photosynthetic light reactions of plants and cyanobacteria, plastocyanin pc1 plays a crucial role as an electron carrier and shuttle protein between two membrane protein complexes.
It is a pigment protein complex with 1114 proteins and several types of organic e. Early research on the role of plastocyanin in photosynthesis esalq. A quantitative description of the groundstate wave function. Phillip and ruth hettleman prize for artistic and scholarly achievement, 2004. In all cyanobacteria studied so far cytochrome c 6 and plastocyanin are functionally interchangeable and share a number of similar physicochemical and structural features that allow them to interact with the same redox partners 9,10. Pdf a comparative structural and functional analysis of. The reduction and oxidization processes by the electron transfer are rapid with the complex between the soluble plastocyanin and the soluble domain in cytochrome f or the p700, and. In contrast to the similarity in the core region as compared to its poplar counterpart, the structure shows some significant differences in loop regions. The rcsb pdb also provides a variety of tools and resources. Plastocyanin pc is a small 10 kda, type 1 copper protein that functions as an electron donor to photosystem i psi from cytochrome cyt f in both chloroplast systems and in some strains of cyanobacteria gross, 1996.
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