The three-dimensional structure of CsmA: a small antenna protein from the green sulfur bacterium Chlorobium tepidum.
The structure of the chlorosome baseplate protein CsmA from Chlorobium tepidum in a 1:1 chloroform:methanol solution was determined using liquid-state NMR spectroscopy. The data reveal that the 59-residue protein is predominantly alpha-helical with a long helical domain extending from residues V6 to L36, containing a putative bacteriochlorophyll a binding domain, and a short helix in the C-terminal part extending from residues M41 to G49. These elements are compatible with a model of CsmA having the long N-terminal alpha-helical stretch immersed into the lipid monolayer confining the chlorosome and the short C-terminal helix protruding outwards, thus available for interaction with the Fenna-Matthews-Olson antenna protein.
Pedersen
Marie Østergaard
MØ
Center for Insoluble Protein Structures (inSPIN), Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry, University of Aarhus, Langelandsgade 140, Aarhus C, Denmark.
Underhaug
Jarl
J
Dittmer
Jens
J
Miller
Mette
M
Nielsen
Niels Chr
NC
D001426:Bacterial Proteins / Q000737:chemistry*; D041883:Chlorobium / Q000378:metabolism*; D019906:Nuclear Magnetic Resonance, Biomolecular; D011487:Protein Conformation
D001426:Bacterial Proteins; C404706:CsmA protein, Chlorobium tepidum