3dn9

Carboxysome Subunit, CcmK1 C-terminal deletion mutant

spinqualitylabelsall models 3dn9, resolution 2.28Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3dn9 is a 6 chain structure with sequence from Synechocystis sp. PCC 6803. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.28Å Ligands: SO4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function CCMK1_SYNY3 May be involved in the formation of the carboxysome, a polyhedral inclusion where RuBisCO is sequestered (By similarity). Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Carboxysomes are primitive bacterial organelles that function as a part of a carbon concentrating mechanism (CCM) under conditions where inorganic carbon is limiting. The carboxysome enhances the efficiency of cellular carbon fixation by encapsulating together carbonic anhydrase and the CO(2)-fixing enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO). The carboxysome has a roughly icosahedral shape with an outer shell between 800 and 1500 A in diameter, which is constructed from a few thousand small protein subunits. In the cyanobacterium Synechocystis sp. PCC 6803, the previous structure determination of two homologous shell protein subunits, CcmK2 and CcmK4, elucidated how the outer shell is formed by the tight packing of CcmK hexamers into a molecular layer. Here we describe the crystal structure of the hexameric shell protein CcmK1, along with structures of mutants of both CcmK1 and CcmK2 lacking their sometimes flexible C-terminal tails. Variations in the way hexamers pack into layers are noted, while sulfate ions bound in pores through the layer provide further support for the hypothesis that the pores serve for transport of substrates and products into and out of the carboxysome. One of the new structures provides a high-resolution (1.3 A) framework for subsequent computational studies of molecular transport through the pores. Crystal and solution studies of the C-terminal deletion mutants demonstrate the tendency of the terminal segments to participate in protein--protein interactions, thereby providing a clue as to which side of the molecular layer of hexameric shell proteins is likely to face toward the carboxysome interior. Insights from multiple structures of the shell proteins from the beta-carboxysome.,Tanaka S, Sawaya MR, Phillips M, Yeates TO Protein Sci. 2009 Jan;18(1):108-20. PMID:19177356 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

Proteopedia Page Contributors and Editors (what is this?)

OCA