Preliminary crystallographic data for the thiamin diphosphate-dependent enzyme pyruvate decarboxylase from brewers' yeast.
Single crystals of the thiamin diphosphate (the vitamin B1 coenzyme)-dependent enzyme pyruvate decarboxylase (EC 4.1.1.1) from brewers' yeast have been grown using polyethylene glycol as a precipitating agent. Crystals of the homotetrameric version alpha 4 of the holoenzyme are triclinic, space group P1, with cell constants a = 81.0, b = 82.4, c = 116.6 A, alpha = 69.5 beta = 72.6, gamma = 62.4 degrees. The crystals are reasonably stable in a rotating anode x-ray beam and diffract to at least 2.5 A resolution. The Vm value of 2.55 A/dalton is consistent with a unit cell containing four subunits with mass of approximately 60 kDa each. Rotation function results with native data indicate strong non-crystallographic 222 symmetry relating the four identical subunits, thus density averaging methods are likely to play a role in the structure determination.
Biocrystallography Laboratory, VA Medical Center, Pittsburgh, Pennsylvania 15240.
F
F
Dyda
W
W
Furey
S
S
Swaminathan
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M
Sax
B
B
Farrenkopf
F
F
Jordan
D046911:Macromolecular Substances; D008970:Molecular Weight; D011767:Pyruvate Decarboxylase / Q000737:chemistry* / Q000302:isolation & purification; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D013835:Thiamine Pyrophosphate; D014961:X-Ray Diffraction
D046911:Macromolecular Substances; D011767:Pyruvate Decarboxylase; D013835:Thiamine Pyrophosphate