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Title
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The crystal structure of complexes between horse liver alcohol dehydrogenase and the coenzyme analogues 3-iodopyridine-adenine dinucleotide and pyridine-adenine dinucleotide.
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Authors
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J.P.Samama,
E.Zeppezauer,
J.F.Biellmann,
C.I.Brändén.
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Ref.
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Eur J Biochem, 1977,
81,
403-409.
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PubMed id
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Abstract
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We have studied the binding of the enzymatically active NAD+ analogue,
3-iodopyridine-adenine dinucleotide, and the inactive analogue, pyridine-adenine
dinucleotide to the enzyme horse liver alcohol dehydrogenase using X-ray
crystallographic methods. These studies were made under such conditions that
crystals of the complexes were isomorphous to apoenzyme crystals. Both analogues
bind in the same conformation. The binding of the adenosine moiety is very
similar to that of ADP-ribose or NADH bound to the enzyme. The conformation and
mode of binding of the remaining portions of the analogue molecules is, however,
quite different. The pyridine ring is not situated in the active-site pocket as
the nicotinamide group in the isomorphous enzyme-NADH-imidazole complex but lies
at the surface of the crevice between the two domains of the subunit,
approximately 1.5 nm away from the catalytically active zinc atom. Lys-228 which
has been shown to be important for NADH dissociation is in this region of the
molecule.
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