SAR11 Cells Rely on Enzyme Multifunctionality To Metabolize a Range of Polyamine Compounds

Abstract

Genome streamlining in SAR11 bacterioplankton has resulted in a small repertoire of genes, yet paradoxically, they consume a substantial fraction of primary production in the oceans. Enzyme multifunctionality, referring to enzymes that are adapted to have broader substrate and catalytic range than canonically defined, is hypothesized to be an adaptation that increases the range of organic compounds metabolized by cells in environments where selection favors genome minimization.