Hierarchic organization of globular proteins. A control study.

In previous work, globular proteins of known structure were shown to be iteratively subdivisible into a hierarchy of disjunct, contiguous-chain regions, ranging in size from whole protein monomers down to individual helices and strands (1, 2). We now report the results of a similar analysis performed on a set of 1000 simulated chain folds that were generated by a method due to Schulz (3). The organization of these simulated proteins was found to be similar to that of authentic molecules. This control study strengthens earlier evidence suggesting that hierarchic architecture is a ubiquitous attribute of protein chain folds.