3DR0

Structure of reduced cytochrome c6 from Synechococcus sp. PCC 7002

Summary for 3DR0

• Entry DOI: 10.2210/pdb3dr0/pdb
• Descriptor: Cytochrome c6, PROTOPORPHYRIN IX CONTAINING FE, SULFATE ION, ... (4 entities in total)
• Functional Keywords: cytochrome, photosynthesis, cyanobacteria, electron transfer, electron transport, heme, iron, metal-binding, thylakoid, transport
• Biological source: Synechococcus sp. PCC 7002 (Agmenellum quadruplicatum)
• Cellular location: Cellular thylakoid lumen (Potential): O30881
• Total number of polymer chains: 3
• Total formula weight: 30380.88

Authors

Bialek, W.,Krzywda, S.,Jaskolski, M.,Szczepaniak, A. (deposition date: 2008-07-10, release date: 2009-07-14, Last modification date: 2023-11-01)

Primary citation

Bialek, W.,Krzywda, S.,Jaskolski, M.,Szczepaniak, A.
Atomic-resolution structure of reduced cyanobacterial cytochrome c6 with an unusual sequence insertion
Febs J., 276:4426-4436, 2009

PubMed Abstract: The structure of the reduced form of cytochrome c(6) from the mesophilic cyanobacterium Synechococcus sp. PCC 7002 has been determined at 1.2 A and refined to an R-factor of 0.107. This protein is unique among all known cytochromes c(6), owing to the presence of an unusual seven-residue insertion, KDGSKSL(44-50), which differs from the insertion found in the recently discovered plant cytochromes c(6A). Furthermore, the present protein is unusual because of its very high content (36%) of the smallest residues (glycine and alanine). The structure reveals that the overall fold of the protein is similar to that of other class I c-type cytochromes, despite the presence of the specific insertion. The insertion is located within the most variable region of the cytochrome c(6) sequence, i.e. between helices II and III. The first six residues [KDGSKS(44-49)] form a loop, whereas the last residue, Leu50, extends the N-terminal beginning of helix III. Several specific noncovalent interactions are found inside the insertion, as well as between the insertion and the rest of the protein. The crystal structure contains three copies of the cytochrome c(6) molecule per asymmetric unit, and is characterized by an unusually high packing density, with solvent occupying barely 17.58% of the crystal volume.

PubMed: 19678839
DOI: 10.1111/j.1742-4658.2009.07150.x

Experimental method

X-RAY DIFFRACTION (1.23 Å)