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Title
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Preliminary crystallographic data for the thiamin diphosphate-dependent enzyme pyruvate decarboxylase from brewers' yeast.
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Authors
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F.Dyda,
W.Furey,
S.Swaminathan,
M.Sax,
B.Farrenkopf,
F.Jordan.
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Ref.
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J Biol Chem, 1990,
265,
17413-17415.
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PubMed id
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Abstract
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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.
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