Consequences of inducing intrinsic disorder in a high-affinity protein–protein interaction

Papadakos, G., Sharma, A., Lancaster, L. E., Bowen, R., Kaminska, R., Leech, A. P., Walker, D. , Redfield, C. and Kleanthous, C. (2015) Consequences of inducing intrinsic disorder in a high-affinity protein–protein interaction. Journal of the American Chemical Society, 137(16), pp. 5252-5255. (doi: 10.1021/ja512607r) (PMID:25856265)

Abstract

The kinetic and thermodynamic consequences of intrinsic disorder in protein–protein recognition are controversial. We address this by inducing one partner of the high-affinity colicin E3 rRNase domain–Im3 complex (Kd ≈ 10–12 M) to become an intrinsically disordered protein (IDP). Through a variety of biophysical measurements, we show that a single alanine mutation at Tyr507 within the hydrophobic core of the isolated colicin E3 rRNase domain causes the enzyme to become an IDP (E3 rRNaseIDP). E3 rRNaseIDP binds stoichiometrically to Im3 and forms a structure that is essentially identical to the wild-type complex. However, binding of E3 rRNaseIDP to Im3 is 4 orders of magnitude weaker than that of the folded rRNase, with thermodynamic parameters reflecting the disorder-to-order transition on forming the complex. Critically, pre-steady-state kinetic analysis of the E3 rRNaseIDP–Im3 complex demonstrates that the decrease in affinity is mostly accounted for by a drop in the electrostatically steered association rate. Our study shows that, notwithstanding the advantages intrinsic disorder brings to biological systems, this can come at severe kinetic and thermodynamic cost.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Walker, Professor Daniel
• Authors: Papadakos, G., Sharma, A., Lancaster, L. E., Bowen, R., Kaminska, R., Leech, A. P., Walker, D., Redfield, C., and Kleanthous, C.
• College/School: College of Medical Veterinary and Life Sciences > School of Infection & Immunity
• Journal Name: Journal of the American Chemical Society
• Publisher: American Chemical Society
• ISSN: 0002-7863
• ISSN (Online): 1520-5126
• Copyright Holders: Copyright © 2015 American Chemical Society
• First Published: First published in Journal of the American Chemical Society 137(16):5252-5255
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher