Letter | Published:

On the Evidence for Partial Gene Duplication from Amino Acid Sequence of Bovine Glutamate Dehydrogenase (reply)

Naturevolume 247page557 (1974) | Download Citation



Dr ENGEL replies: Williams and Wilkins have done the evidence less than justice in two respects: (1) Our disagreement hinges upon the choice of a basis for statistical assessment of the observed sequence match. Absolute validity can neither be attained nor defined; one can only attempt to select reasonable criteria. My original probability calculation may have been too arbitrarily exclusive but, equally, Williams's and Wilkins's computer-search is too arbitrarily all-inclusive. To ignore relevant information must bias the calculation against discovery of the truth. The evidence for the importance of lysine-126 comes not only from studies of kinetics and binding (see ref. 1), but also from sequence comparisons which show that lysine-126 is in a conserved region2–4. This being so, even fifty may be an overestimate of the necessary number of sequences containing lysine-126 to be compared.

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    Chen, S. S., and Engel, P. C., Eur. J. Biochem. (in the press).

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    Moon, K., Piszkiewicz, D., and Smith, E. L., Proc. natn. Acad. Sci. U.S.A., 69, 1380 (1972).

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    Wootton, J. C., Chambers, G. K., Taylor, J. G., and Fincham, J. R. S., Nature, 241, 42 (1973).

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    Holbrook, J. J., Roberts, P. A., and Wallis, R. B., Biochem. J., 133, 165 (1973).

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    Engel, P. C., Nature, 24l, 118 (1973).

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    Smith, E. L., Landon, M., Piszkiewicz, D., Brattin, W. J., Langley, T. J., and Melamed, M. D., Proc. natn. Acad. Sci. U.S.A., 67, 724 (1970).

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    Forcina, B. G., Ferri, G., Zapponi, M. C., and Ronchi, S., Eur. J. Biochem., 20, 535 (1971).

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  1. Department of Biochemistry, University of Sheffield, S10 2TN

    • P. C. ENGEL


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