Before revision:  By reconciling two approaches for analyzing correlations in multiple sequence alignments, we uncover a new class of coevolving units , called 'sectons'. Sectons provide a conceptual link between coevolving contacts and sectors. The methods and results that we present are general , and relevant beyond protein structures .
After revision:  By reconciling two approaches for analyzing correlations in multiple sequence alignments, we link these two findings together and with coevolving units of intermediate size, called `sectons', which are shown to provide additional information. By extending the analysis to the co-occurrence of orthologous genes in bacterial genomes, we also show that the methods and results that we present are general , and relevant beyond protein structures .