Two new high-resolution crystal structures of carboxysome pentamer proteins reveal high structural conservation of CcmL orthologs among distantly related cyanobacterial species
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Cyanobacteria have evolved a unique carbon fixation organelle known as the carboxysome that compartmentalizes the enzymes RuBisCO and carbonic anhydrase. This effectively increases the local CO2 concentration at the active site of RuBisCO and decreases its relatively unproductive side reaction with oxygen. Carboxysomes consist of a protein shell composed of hexameric and pentameric proteins arranged in icosahedral symmetry. Facets composed of hexameric proteins are connected at the vertices by pentameric proteins. Structurally homologous pentamers and hexamers are also found in heterotrophic bacteria where they form architecturally related microcompartments such as the Eut and Pdu organelles for the metabolism of ethanolamine and propanediol, respectively. Here we describe two new high-resolution structures of the pentameric shell protein CcmL from the cyanobacteria Thermosynechococcus elongatus and Gloeobacter violaceus and provide detailed analysis of their characteristics and comparison with related shell proteins.
KeywordsCyanobacteria Microcompartment Carboxysome CcmL
We would like to thank the entire staff at the Advanced Light Source, Lawrence Berkeley National Laboratory, which is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. CAK and SCW are supported by the NSF (EF1105897). MS was supported by a Swiss National Science Foundation Postdoctoral Fellowship.
- Afonine PV, Grosse-Kunstleve RW, Echols N, Headd JJ, Moriarty NW, Mustyakimov M, Terwilliger TC, Urzhumtsev A, Zwart PH, Adams PD (2012) Towards automated crystallographic structure refinement with phenix.refine. Acta Crystallogr D 68:352–367. doi: 10.1107/S0907444912001308 PubMedCrossRefGoogle Scholar
- Bobik TA, Havemann GD, Busch RJ, Williams DS, Aldrich HC (1999) The propanediol utilization (pdu) operon of Salmonella enterica serovar Typhimurium LT2 includes genes necessary for formation of polyhedral organelles involved in coenzyme B12-dependent 1,2-propanediol degradation. J Bacteriol 181(19):5967–5975PubMedGoogle Scholar
- Cai F, Sutter M, Cameron JC, Stanley DN, Kinney JN, Kerfeld CA (2013) The structure of CcmP, a tandem bacterial microcompartment domain protein from the beta-carboxysome, forms a subcompartment within a microcompartment. J Biol Chem 288(22):16055–16063. doi: 10.1074/jbc.M113.456897 PubMedCrossRefGoogle Scholar
- Forouhar F, Kuzin A, Seetharaman J, Lee I, Zhou W, Abashidze M, Chen Y, Yong W, Janjua H, Fang Y, Wang D, Cunningham K, Xiao R, Acton TB, Pichersky E, Klessig DF, Porter CW, Montelione GT, Tong L (2007) Functional insights from structural genomics. J Struct Funct Genomics 8(2–3):37–44. doi: 10.1007/s10969-007-9018-3 PubMedCrossRefGoogle Scholar
- Price GD, Badger MR (1989) Isolation and characterization of high CO(2)-requiring-mutants of the cyanobacterium Synechococcus PCC7942: two phenotypes that accumulate inorganic carbon but are apparently unable to generate CO(2) within the carboxysome. Plant Physiol 91(2):514–525PubMedCrossRefGoogle Scholar
- Winn MD, Ballard CC, Cowtan KD, Dodson EJ, Emsley P, Evans PR, Keegan RM, Krissinel EB, Leslie AG, McCoy A, McNicholas SJ, Murshudov GN, Pannu NS, Potterton EA, Powell HR, Read RJ, Vagin A, Wilson KS (2011) Overview of the CCP4 suite and current developments. Acta Crystallogr D Biol Crystallogr 67(Pt 4):235–242. doi: 10.1107/S0907444910045749 PubMedCrossRefGoogle Scholar