Location of an extrinsic label in the primary and tertiary structure of bacteriorhodopsin.
We located a heavy metal label, mercurilated phenylglyoxal, in both the primary sequence and in the tertiary structure of bacteriorhodopsin. This label modified arginines 225 and 227, which are on the COOH-terminal helix (G). In the projected electron potential difference map, the major site is close to the central inner helix. From this result we conclude that helix 1 could not be the COOH-terminal helix G. We tested the multiple isomorphous replacement method for obtaining phases for purple membrane by electron diffraction.
D000595:Amino Acid Sequence; D001436:Bacteriorhodopsins; D002338:Carotenoids; D003488:Cyanogen Bromide; D006217:Halobacterium; D009941:Organomercury Compounds; D010446:Peptide Fragments; D010658:Phenylglyoxal; D011485:Protein Binding; D011487:Protein Conformation
D009941:Organomercury Compounds; D010446:Peptide Fragments; D002338:Carotenoids; D001436:Bacteriorhodopsins; D010658:Phenylglyoxal; D003488:Cyanogen Bromide