Crystal structure of Escherichia coli-expressed Haloarcula marismortui bacteriorhodopsin I in the trimeric form. oleh Vitaly Shevchenko, Ivan Gushchin, Vitaly Polovinkin, Ekaterina Round, Valentin Borshchevskiy, Petr Utrobin, Alexander Popov, Taras Balandin, Georg Büldt, Valentin Gordeliy