VAT-1 from Torpedo is a membranous homologue of zeta crystallin.
VAT-1 is a major protein from Torpedo synaptic vesicles. A protein data-base search revealed a striking homology to zeta crystallin from guinea pig lens. The overall amino-acid identity is 27%, and 58% similarity is reached by including conserved substitutions. The highest similarity (60% to 85%) between the two proteins is observed in five discrete domains, which are also conserved in zinc-dependent dehydrogenases, particularly in the alcohol dehydrogenase family. The cofactor-binding domain of oxidoreductases is conserved in VAT-1 and in zeta crystallin. VAT-1 preferably binds NADPH in the presence of zinc. In contrast with its homologous proteins, VAT-1 is an integral membrane protein of synaptic vesicles.
Linial
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Department of Biological Chemistry, Alexander Silverman Institute of Life Science, Hebrew University, Jerusalem, Israel.
Levius
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O
D000595:Amino Acid Sequence; D000818:Animals; D003459:Crystallins / Q000737:chemistry*; D008565:Membrane Proteins / Q000737:chemistry*; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013572:Synaptic Vesicles / Q000737:chemistry*; D014101:Torpedo / Q000235:genetics*
D003459:Crystallins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; C063277:VAT-1 protein, Torpedo