Cytochrome f
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Cytochrome f is the largest subunit of cytochrome b6f complex. In its structure and functions, the cytochrome b6f complex bears extensive analogy to the cytochrome bc1 complex of mitochondria and phot
cytochrome f from the b6f complex of Phormidium laminosum
Alpha helix
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An alpha helix is a sequence of amino acids in a protein that are twisted into a coil.
Cytochrome f
…structure. The small domain is inserted between beta-strands F and G of the large domain and is an all-beta domain. The haem nestles between two short helices at the N terminus of cyt f. Within the second helix is the sequence motif for the c-type cytochromes, CxxCH (residues 21–25), which is covalently…
Contrast of helix end views between α (offset squarish) vs 310 (triangular)
Ramachandran plot (φ, ψ plot), with data points for α-helical residues forming a dense diagonal cluster below and left of center, around the global energy minimum for backbone conformation.
An α-helix in ultrahigh-resolution electron density contours, with oxygen atoms in red, nitrogen atoms in blue, and hydrogen bonds as green dotted lines (PDB file 2NRL, 17–32). The N-terminus is at the top, here.
Leucine zipper coiled-coil helices & DNA-binding helices: transcription factor Max (PDB file 1HLO)