Figure 1.

Principle of QSalign^HET to annotate the physiological relevance of hetero-oligomeric protein quaternary structures

Hydroxynitrile lyase is a heterohexameric enzyme in Klebsiella oxytoca (PDB: 1EEX). A glycerol dehydratase from Klebsiella pneumoniae shows a similar quaternary structure (PDB: 1IWP, TM-score 0.9, root-mean-square deviation 1.14 Å), although they share 63% sequence identity on average. Such conservation suggests that the quaternary structure (QS) of both of these hexamers is physiologically relevant. This information enables inferring that the QS of a different entry (PDB: 1MMF), which shares 100% sequence identity with 1IWP, may have missing subunits.