JTW's Evolutionary Origins - Author: Lahav, Noam

The Antiquity of Coenzymes and their Evolutionary Conservation

"Many Enzymes cannot function properly without the presence of an additional chemical entitiy bound to the enzyme molecule, called the coenzyme.

It was known for a long time that many of the coenzymes are nucleotides or contain cyclic nitogenous bases derivable from nucleotides.

In line with the principle of continuity, it was suggested by H.B. White as early as in 1976 that coenzymes are 'vestiges of nucleic acid enzymes which preceeded the evolution of the ribosomal protein synthesis.'

These early catalysts have changed little during the hundreds of millions, probably billions, of years of evolution, and they attest to the antiquity of the biochemical reactions in which they are involved in modern cells.

Presumably, during the eons of evolutionary time since the emergence of coenzymes, many catalytic functions and structures gradually emerged and were added to the more ancient biocatalytic coenzymes."

[Lahav, 1999 pp.181]

"The principle of many users: According to H.B. White (1976), it is extremely unlikely for a structure that serves as a cofactor in many reactions to change while maintaining efficiency and specificity.

Most cofactors are relatively small, with molecular weights less than about 600, and enzymes can bind and orient them for their catalytic functions by recognizing the cofactor surface.

Indeed, this requirement is reflected in deep cofactor-binding clefts found in modern protein enzymes. With such specific recognition elements, cofactors are not likely to change easily (see Giver et. al. 1994)."

[Lahav, 1999 pp.181-182]

• Lahav, Noam
  • Biogenesis: Theories of Life's Origins
  • Oxford University Press, Inc.
  • QH 325.L24 1999

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