Crystal packing of the c(6)-type cytochrome OmcF from Geobacter sulfurreducens is mediated by an N-terminal Strep-tag II.
The putative outer membrane c-type cytochrome OmcF from Geobacter sulfurreducens contains a single haem group and shows homology to soluble cytochromes c(6), a class of electron-transfer proteins that are typically found in cyanobacterial photosynthetic electron-transfer chains. OmcF was overexpressed heterologously in Escherichia coli as an N-terminal Strep-tag II fusion protein and isolated using streptactin-affinity chromatography followed by size-exclusion chromatography. The structure was solved by Fe SAD using data collected to a resolution of 1.86 A on a rotating copper-anode X-ray generator. In the crystal, packing interactions in one dimension were exclusively mediated through the Strep-tag II sequence. The tag and linker regions were in contact with three further monomers of OmcF, leading to a well defined electron-density map for this engineered and secondary-structure-free region of the molecule.
Lukat
Peer
P
Institut für Mikrobiologie und Genetik, Georg-August-Universität Göttingen, Justus-von-Liebig-Weg 11, 37077 Göttingen, Germany.
Hoffmann
Maren
M
Einsle
Oliver
O
D000345:Affinity Labels / Q000737:chemistry; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry; D003460:Crystallization; D018360:Crystallography, X-Ray; D045365:Cytochromes c6 / Q000737:chemistry*; D045302:Geobacter / Q000737:chemistry*; D008958:Models, Molecular; D009842:Oligopeptides / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry
D000345:Affinity Labels; C099517:Ala-Trp-Arg-His-Pro-Gln-Phe-Gly-Gly; D001425:Bacterial Outer Membrane Proteins; D045365:Cytochromes c6; D009842:Oligopeptides; D011994:Recombinant Proteins