Cyrus Chothia obituary

Biochemist whose work was at the cutting edge of the understanding of protein structures, their function and evolution

Taxonomy - the classification of objects according to their relationships to one another - conjures up images of 19th-century amateur naturalists measuring fossils or counting the stamens of flowering plants.

The biochemist Cyrus Chothia, who has died aged 77, took a taxonomic approach to research at the cutting edge of molecular biology, organising the bewildering variety of protein structures revealed by techniques such as x-ray crystallography and genome sequencing into coherent family trees.