Structure and heme environment of ferrocytochrome c553 from 1H NMR studies.

摘要: Cytochrome c553 is a photosynthetic electron transport protein found in algae and cyanobacteria. We have purified cytochromes from five cyanobacteria studied the structures of ferrocytochromes by 1H NMR spectroscopy at 360 470 MHz. Using standard techniques comparing amino acid sequences four with their spectra, we assigned spectrum Aphanizomenon flos-aquae 18 resonances to specific residues 12 heme protons. Steady state truncated driven nuclear Overhauser enhancement experiments indicate that tyrosine methionine are located near pyrrole ring IV phenylalanine alpha-mesoproton. The general folding cytochrome backbone appears resemble Pseudomonas aeruginosa c551, but chirality axial methine sulfur R, same as horse heart c.