The protein subunits in a virus capsid are multiply redundant, i.e. present in many copies per particle.
Since there are 13 actin subunits per helical turn, myosin V has a relatively long step length of 74 nm.
Substrate binding to this site is thought to affect enzyme activity by altering the relative positions of the two subunits of ribonucleotide reductase.
Different combinations of a & b subunits make a large variety of integrins with different binding specificity.
Whole ribosomes and their individual subunits can be crystallized in the same way as proteins.