Three acidic residues Glu31, Asp142 and Asp171 of Aspergillus oryzae cutinase CutL1 are required for both interaction with hydrophobin RolA and consequent stimulation of polyester8208;degradation.

Kimihide Muragaki, Kenji Uehara, Toru Takahashi, Fumihiko Hasegawa, Keietsu Abe

Author address: 

Grad. Sch. Agric. Sci., Tohoku Univ.   NRIB, Japan   New Industry Creation Hatchery Center, Tohoku University  

Abstract: 

Hydrophobins are amphipathic proteins, and are ubiquitous among filamentous fungi. When the industrial fungus Aspergillus oryzae is grown in a submerged medium containing a biodegradable polyester polybutylene succinate8208; coadipate (PBSA) as a sole carbon source, cutinase CutL1 and hydrophobin RolA are simultaneously secreted into the medium. RolA attached to the surface of PBSA particles specifically recruits CutL1, resulting in stimulation of PBSA hydrolysis (1). In our previous study, we identified amino acid residues involved in the RolA8208;CutL1 interaction by means of chemical modification and site8208;directed mutagenesis of RolA and CutL1. As a result, we found that His32 and Lys34 of RolA and Glu31, Asp142, Asp171 of CutL1 are involved in the RolA8208;CutL1 interaction. In the present study, to quantitatively elucidate the role of the three acidic amino acid residues of CutL1 in the RolA8208; CutL1 interaction, we characterized kinetics of the interaction between CutL1 variants of the three residues and wild type RolA by using Quartz crystal microbalance (QCM). The QCM analysis revealed that replacement of the three acidic amino acid residues of CutL1 to serine caused increases in KD values for interaction with RolA. In conclusion, Glu31, Asp142 and Asp171 of CutL1 are critically required for the RolA8208;CutL1 interaction by multivalent effect. (1) Takahashi et al. Mol Microbiol. 57:1780 (2005)
2012

abstract No: 

PR8.35

Full conference title: 

11 th European Conference on Fungal Genetics
    • ECFG 11th (2012)