Functional and structural characterisation of a viral cytochrome b5.

Highlights: [•] Structure of a novel virus encoded cytochrome b5 solved. [•] The protein has identical spectral properties to purified human cytochrome b5. [•] The protein can substitute for yeast cytochrome b5 in the P450 51 mediated sterol 14α-demethylation. [•] The protein lacks a hydrophobic C-terminal anchor and is the first cytosolic cytochrome b5 characterised. [•] Suggests the importance of cytochrome b5 metabolic activity at the extremes of cellular scale. [Copyright &y& Elsevier]