A conserved helical capping hydrogen bond in PAS domains controls signaling kinetics in the superfamily prototype photoactive yellow protein.

ABSTRACT: PAS domains form a divergent protein superfamily with more than 20 000 members that perform a wide array of sensing and regulatory functions in all three domains of life. Only nine residues are well-conserved in PAS domains, with an Asn residue at the start of α-helix 3 showing the strongest conservation. The molecular functions of these nine conserved residues are unknown. We use static and time-resolved visible and FTIR spectroscopy to investigate receptor activation in the photosensor photoactive yellow protein (PYP), a PAS domain prototype. The N43A and N43S mutants allow an investigation of the role of side-chain hydrogen bonding at this conserved position. The mutants exhibit a blue-shifted visible absorbance maximum and up-shifted chromophore pK(a). Disruption of the hydrogen bonds

SUBMITTER: Kumauchi M 

PROVIDER: S-EPMC2999845 | biostudies-literature | 2010 Nov

REPOSITORIES: biostudies-literature