c-di-AMP assists osmoadaptation by regulating the potassium transporters KimA and KtrCD.

Many bacteria and some archaea produce the second messenger cyclic diadenosine monophosphate (c-di-AMP). c-di-AMP controls the uptake of osmolytes in Firmicutes, including the human pathogen , making it essential for growth. c-di-AMP is known to directly regulate several potassium channels involved in osmolyte transport in species such as and , but whether this same mechanism is involved in , or even whether similar ion channels were present, was not known.

Changing the substrate specificity of P450cam towards diphenylmethane by semi-rational enzyme engineering.

A focused library comprising nine residues of the active site of P450cam monooxygenase resulting in ∼ 300,000 protein variants was screened for activity on diphenylmethane (DPM). The assay was based on the depletion of NADH by an in vitro reconstituted P450cam system in a 96-well scale. The throughput was increased by the parallel cultivation, purification and analysis of 20 variants per well (cluster screening).