| Literature References | 1. MAVROTHALASSITIS, G., TZIMAGIORGIS, G., MITSIALIS, A., ZANNIS, V.,
PLAITAKIS, A., PAPAMATHEAKIS, J. AND MOSCHONAS, N.
Isolation and characterization of cDNA clones encoding human liver
glutamate dehydrogenase - Evidence for a small gene family.
PROC.NATL.ACAD.SCI.U.S.A. 85(10) 3494-3498 (1988).
2. MOYE, W.S., AMURO, N., RAO, J.K.M. AND ZALKIN, H.
Nucleotide sequence of yeast GDH1 encoding nicotinamide adenine dinucleotide
phosphate-dependent glutamate dehydrogenase.
J.BIOL.CHEM. 260(14) 8502-8508 (1985).
3. OKAZAKI, N., HIBINO, Y., ASANO, Y., OHMORI, M., NUMAO, N. AND KONDO, K.
Cloning and nucleotide sequencing of phenylalanine dehydrogenase gene of
Bacillus sphaericus.
GENE 63(2) 337-341 (1988).
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| Documentation | Glutamate, leucine and phenylalanine dehydrogenases are structurally
and functionally related. They contain a Gly-rich region containing a
conserved Lys residue, which has been implicated in the catalytic activity,
in each case a reversible oxidative deamination reaction. Glutamate
dehydrogenase catalyses the reversible oxidative deamination of L-glutamate
to alpha-ketoglutarate, using NAD and/or NADP as cofactors [1]. Two separate
enzymes are present in yeasts: the NADP-dependent enzyme, which catalyses
the amination of alpha-ketoglutarate to L-glutamate; and the NAD-dependent
enzyme, which catalyses the reverse reaction [2] - this form links the
L-amino acids with the Krebs cycle, which provides a major pathway for
metabolic interconversion of alpha-amino acids and alpha-keto acids [1].
Leucine dehydrogenase is an NAD-dependent enzyme that catalyses the
reversible deamination of leucine and several other aliphatic amino acids to
their keto analogues. Phenylalanine dehydrogenase is also NAD-dependent and
catalyses the reversible oxidative deamination of L-phenylalanine to form
phenyl-pyruvate [3].
GLFDHDRGNASE is a 4-element fingerprint that provides a signature for
glutamate, leucine and phenylalanine dehydrogenases. The fingerprint was
derived from an initial alignment of 6 sequences: motif 1 includes part of
the region encoded by PROSITE pattern GLF_DEHYDROGENASE (PS00074), which
contains the conserved Gly-rich region presumed important in the catalytic
mechanism. Two iterations on OWL21.1 were required to reach convergence,
at which point a true set comprising 29 sequences was identified. Two
partial matches were also found, both of which are fragments.
An update on SPTR37_9f identified a true set of 70 sequences, and 2
partial matches.
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