The enzymatic reaction-induced configuration change of the prosthetic group PQQ of methanol dehydrogenase.

Methanol dehydrogenase is a heterotetrameric enzyme containing the prosthetic group pyrroloquinoline quinone (PQQ), which catalyzes the oxidation of methanol to formaldehyde. The crystal structure of methanol dehydrogenase from Methylophilus W3A1, previously determined at high resolution, exhibits a non-planar configuration of the PQQ ring system and lends support for a hydride transfer mechanism of the enzymatic reaction catalyzed by the enzyme. To investigate why PQQ is in the C5-reduced form and to better understand the catalytic mechanism of the enzyme, three structures of this enzyme in a new crystal form have been determined at higher resolution.

Structure of the F58W mutant of cytochrome b5: the mutation leads to multiple conformations and weakens stacking interactions.

Phe58 of cytochrome b5 is involved in stacking interactions with heme and the axial ligand His63. To elucidate the contribution of the stacking interactions to protein stability, the crystal structures of the F58Y and F58W mutants were determined at high resolution. The structure of the F58Y mutant is basically the same as that of the wild-type protein.

The three-dimensional structure and X-ray sequence reveal that trichomaglin is a novel S-like ribonuclease.

Trichomaglin is a protein isolated from root tuber of the plant Maganlin (Trichosanthes Lepiniate, Cucurbitaceae). The crystal structure of trichomaglin has been determined by multiple-isomorphous replacement and refined at 2.2 A resolution.

Structures of V45E and V45Y mutants and structure comparison of a variety of cytochrome b5 mutants.

Val45 is a highly conserved residue and a component of the heme-pocket wall of cytochrome b(5). The crystal structures of cytochrome b(5) mutants V45E and V45Y have been determined at high resolution. Their overall structures were very similar to that of the wild-type protein.