TY - JOUR
T1 - Comparison of the physical characteristics of chlorosomes from three different phyla of green phototrophic bacteria
AU - Adams, Peter G.
AU - Cadby, Ashley J.
AU - Robinson, Benjamin
AU - Tsukatani, Yusuke
AU - Tank, Marcus
AU - Wen, Jianzhong
AU - Blankenship, Robert E.
AU - Bryant, Donald A.
AU - Hunter, C. Neil
N1 - Funding Information:
C.N.H. acknowledges financial support from the Biotechnology and Biological Sciences Research Council (UK) . P.G.A. was supported by a doctoral studentship from the Biotechnology and Biological Sciences Research Council (UK). This work was supported as part of the Photosynthetic Antenna Research Center (PARC), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC 0001035 . PARC's role was to partially fund the Multimode VIII AFM system and to provide partial support for J.W. and C.N.H. Work performed in the laboratory of D.A.B. was funded by grant DE-FG02-94ER20137 from the U.S. Department of Energy . A.J.C. was funded by the EPSRC grant EP/E059716/1 ; B.R. was funded through an EPSRC doctoral training award.
PY - 2013
Y1 - 2013
N2 - Chlorosomes, the major antenna complexes in green sulphur bacteria, filamentous anoxygenic phototrophs, and phototrophic acidobacteria, are attached to the cytoplasmic side of the inner cell membrane and contain thousands of bacteriochlorophyll (BChl) molecules that harvest light and channel the energy to membranebound reaction centres. Chlorosomes from phototrophs representing three different phyla, Chloroflexus (Cfx.) aurantiacus, Chlorobaculum (Cba.) tepidum and the newly discovered "Candidatus (Ca.) Chloracidobacterium (Cab.) thermophilum" were analysed using PeakForce Tapping atomic force microscopy (PFT-AFM). Gentle PFT-AFM imaging in buffered solutions that maintained the chlorosomes in a near-native state revealed ellipsoids of variable size, with surface bumps and undulations that differ between individual chlorosomes. Cba. tepidum chlorosomes were the largest (133 × 57 × 36 nm; 141,000 nm3 volume), compared with chlorosomes from Cfx. aurantiacus (120 × 44 × 30 nm; 84,000 nm3) and Ca. Cab. thermophilum (99 × 40 × 31 nm; 65,000 nm3). Reflecting the contributions of thousands of pigment-pigment stacking interactions to the stability of these supramolecular assemblies, analysis by nanomechanical mapping shows that chlorosomes are highly stable and that their integrity is disrupted only by very strong forces of 1000-2000 pN. AFM topographs of Ca. Cab. thermophilum chlorosomes that had retained their attachment to the cytoplasmic membrane showed that this membrane dynamically changes shape and is composed of protrusions of up to 30 nm wide and 6 nmabove themica support, possibly representing different protein domains. Spectral imaging revealed significant heterogeneity in the fluorescence emission of individual chlorosomes, likely reflecting the variations in BChl c homolog composition and internal arrangements of the stacked BChls within each chlorosome. Crown
AB - Chlorosomes, the major antenna complexes in green sulphur bacteria, filamentous anoxygenic phototrophs, and phototrophic acidobacteria, are attached to the cytoplasmic side of the inner cell membrane and contain thousands of bacteriochlorophyll (BChl) molecules that harvest light and channel the energy to membranebound reaction centres. Chlorosomes from phototrophs representing three different phyla, Chloroflexus (Cfx.) aurantiacus, Chlorobaculum (Cba.) tepidum and the newly discovered "Candidatus (Ca.) Chloracidobacterium (Cab.) thermophilum" were analysed using PeakForce Tapping atomic force microscopy (PFT-AFM). Gentle PFT-AFM imaging in buffered solutions that maintained the chlorosomes in a near-native state revealed ellipsoids of variable size, with surface bumps and undulations that differ between individual chlorosomes. Cba. tepidum chlorosomes were the largest (133 × 57 × 36 nm; 141,000 nm3 volume), compared with chlorosomes from Cfx. aurantiacus (120 × 44 × 30 nm; 84,000 nm3) and Ca. Cab. thermophilum (99 × 40 × 31 nm; 65,000 nm3). Reflecting the contributions of thousands of pigment-pigment stacking interactions to the stability of these supramolecular assemblies, analysis by nanomechanical mapping shows that chlorosomes are highly stable and that their integrity is disrupted only by very strong forces of 1000-2000 pN. AFM topographs of Ca. Cab. thermophilum chlorosomes that had retained their attachment to the cytoplasmic membrane showed that this membrane dynamically changes shape and is composed of protrusions of up to 30 nm wide and 6 nmabove themica support, possibly representing different protein domains. Spectral imaging revealed significant heterogeneity in the fluorescence emission of individual chlorosomes, likely reflecting the variations in BChl c homolog composition and internal arrangements of the stacked BChls within each chlorosome. Crown
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U2 - 10.1016/j.bbabio.2013.07.004
DO - 10.1016/j.bbabio.2013.07.004
M3 - Article
C2 - 23867748
AN - SCOPUS:84881008838
VL - 1827
SP - 1235
EP - 1244
JO - Biochimica et Biophysica Acta - Bioenergetics
JF - Biochimica et Biophysica Acta - Bioenergetics
SN - 0005-2728
IS - 10
ER -