Jaap J. Beintema

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The RNase A superfamily has been important in biochemical, structural, and evolutionary studies and is believed to be the sole vertebrate-specific enzyme family. To understand the origin and diversification of the superfamily, we here determine its entire repertoire in the sequenced genomes of human, mouse, rat, and chicken. We report a previously unnoticed(More)
Crustacean and cheliceratan hemocyanins (oxygen-transport proteins) and insect hexamerins (storage proteins) are homologous gene products, although the latter do not bind oxygen and do not possess the copper-binding histidines present in the hemocyanins. An alignment of 19 amino acid sequences of hemocyanin subunits and insect hexamerins was made, based on(More)
The primary structure of pancreatic ribonuclease from langur (Presbytis entellus) has been determined. This sequence differs from that of human pancreatic ribonuclease at 14 (11%) of the amino acid positions. Eight of these 14 differences involve changes of charge, with the langur enzyme having five fewer positive charges than the human enzyme. The(More)
The cDNA of mouse pancreatic mRNA has been cloned. After the library was screened with a rat ribonuclease cDNA probe, the positive clones were isolated and sequenced. There were no differences from the previously determined protein sequence. The mRNA codes for a preribonuclease of 149 amino acid residues including a signal peptide of 25 amino acids. The 3'(More)
In a study of mammalian ribonuclease evolutionary rates, we applied the Fitch-Bruschi correction to reduce the bias caused by an unequal sampling of taxa in different lineages. The correction was clearly appropriate but only up to a point. The analysis showed that the sampling of taxa within the pecora was sufficiently intense that no correction for unseen,(More)
Amino acid sequences of 39 mammalian ribonucleases have been used to construct trees by the maximum parsimony procedure. These trees are in fairly good agreement with the biological classification of the species involved. In the branching order of the six investigated eutherian mammalian orders, the edentates diverge first, followed , probably, by the(More)
Several trees of amino acid sequences of rodent insulins were derived with the maximum-parsimony procedure. Possible orthologous and paralogous relationships were investigated. Except for a recent gene duplication in the ancestor of rat and mouse, there are no strong arguments for other paralogous relationships. Therefore, a tree in agreement with other(More)
A more than 10-fold difference in the specificity and catalytic efficiency for 1-naphthyl esters was measured between two allozymes of esterase-4 from Drosophila mojavensis. This difference is mainly caused by a difference in the affinity for the 1-naphthyl esters. The amino acid compositions of the allozymes are not significantly different, which means(More)
More than half of all mammalian species belong to the order of the rodents. Although many phylogenetic relationships among rodents have been established beyond doubt, others are not yet established. The phylogenetic position of the Cteno-dactylidae (gundis) was discussed in several contributions to a symposium in Paris in 1984 (Luckett and Hartenberger(More)