Cooperative effects in the binding of pyridoxal 5′‐phosphate to mitochondrial apo‐aspartate aminotransferase

Garzillo, Anna Maria Vittoria; Marino, Gennaro; Pispisa, B.

doi:10.1016/0014-5793(84)81317-4

Cited by 2 publications

(1 citation statement)

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“…The last 40 years has witnessed several conflicting reports on whether other AATases are cooperative enzymes [19][20][21][22][23][24][25][26] ; however the presence of allosteric communication between the active sites of eAATase has not been reported. This controversy has also arisen with other aminotransferases such as glutamate-1-semialdehyde aminotransferase for which crystal structures from Synechococcus 27 and Bacillus subtilis 28 show asymmetric and symmetric active sites, respectively.…”

Section: Allosteric Communication Between Active Sitesmentioning

confidence: 99%

Engineering homooligomeric proteins to detect weak intersite allosteric communication: Aminotransferases, a case study

Deu

Kirsch

2011

Protein Science

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The existence of low levels of intersubunit communication in homooligomeric enzymes is often difficult to discover, as the identical active sites cannot be probed individually to dissect their interdependent contributions. The homodimeric paralogs, E. coli aspartate-(AATase) and tyrosine aminotransferase (TATase), have not been demonstrated to show allostery. To address this question, we engineered a hybrid aminotransferase containing two distinct catalytic pockets: an AATase and a TATase site. The TATase/AATase hybrid was constructed by grafting an engineered TATase active site into one of the catalytic pockets of E. coli AATase. Each active site conserves its specific catalytic and inhibitor binding properties, and the hybrid catalyzes simultaneously each aminotransferase reaction at the respective site. Importantly, association of a selective inhibitor into one of the catalytic pockets decreases the activity of the second active site by up to 25%, thus proving unequivocally the existence of allosteric communication between active sites. The procedure may be applicable to other homologous sets of enzymes.

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