Send to

Choose Destination
See comment in PubMed Commons below
Proc Natl Acad Sci U S A. 1987 May;84(9):2580-4.

Mammalian alcohol dehydrogenases of separate classes: intermediates between different enzymes and intraclass isozymes.


A comparison of the structure of class II human liver alcohol dehydrogenase (alcohol:NAD+ oxidoreductase, EC (containing pi subunits) with those of the human class I isozymes (containing alpha, beta, and gamma subunits) reveals differences at about 40% of all positions. Variations are large for active-site regions, the segment around the second zinc atom, and for segments involved in subunit interactions. The two classes of alcohol dehydrogenase have diverged to exhibit structural differences to about half the extent of those between alcohol and polyol dehydrogenases. Hence, the two classes of alcohol dehydrogenase represent steps in enzyme rather than isozyme divergence. An evolutionary scheme that relates different types of zinc-containing mammalian dehydrogenases to one another encompasses at least three levels of gene duplication subsequent to the early step(s) of assembly of building unit(s). The first level of duplication results in the formation of now clearly different enzymes. The second level concerns the various classes of alcohol dehydrogenase, forming steps between typical enzymes and isozymes. The third level encompasses recent and multiple duplications in isozyme evolution of alcohol dehydrogenases. This scheme, linking zinc-containing dehydrogenases at different levels, resembles that in other protein families and reflects general patterns in protein relationships.

[PubMed - indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk