Linkage via K27 Bestows Ubiquitin Chains with Unique Properties among Polyubiquitins

TY - JOUR

T1 - Linkage via K27 Bestows Ubiquitin Chains with Unique Properties among Polyubiquitins

AU - Castañeda, Carlos A

AU - Dixon, Emma K

AU - Walker, Olivier

AU - Chaturvedi, Apurva

AU - Nakasone, Mark A

AU - Curtis, Joseph E

AU - Reed, Megan R

AU - Krueger, Susan

AU - Cropp, T Ashton

AU - Fushman, David

N1 - Funding - NSF (DBI1040158, CHE-1265821) NIH (GM065334, GM021248, GM084396, 1S10OD012254) Copyright © 2016 Elsevier Ltd. All rights reserved.

PY - 2016/3/1

Y1 - 2016/3/1

N2 - Polyubiquitination, a critical protein post-translational modification, signals for a diverse set of cellular events via the different isopeptide linkages formed between the C terminus of one ubiquitin (Ub) and the ɛ-amine of K6, K11, K27, K29, K33, K48, or K63 of a second Ub. We assembled di-ubiquitins (Ub2) comprising every lysine linkage and examined them biochemically and structurally. Of these, K27-Ub2 is unique as it is not cleaved by most deubiquitinases. As this remains the only structurally uncharacterized lysine linkage, we comprehensively examined the structures and dynamics of K27-Ub2 using nuclear magnetic resonance, small-angle neutron scattering, and in silico ensemble modeling. Our structural data provide insights into the functional properties of K27-Ub2, in particular that K27-Ub2 may be specifically recognized by K48-selective receptor UBA2 domain from proteasomal shuttle protein hHR23a. Binding studies and mutagenesis confirmed this prediction, further highlighting structural/recognition versatility of polyubiquitins and the potential power of determining function from elucidation of conformational ensembles.

AB - Polyubiquitination, a critical protein post-translational modification, signals for a diverse set of cellular events via the different isopeptide linkages formed between the C terminus of one ubiquitin (Ub) and the ɛ-amine of K6, K11, K27, K29, K33, K48, or K63 of a second Ub. We assembled di-ubiquitins (Ub2) comprising every lysine linkage and examined them biochemically and structurally. Of these, K27-Ub2 is unique as it is not cleaved by most deubiquitinases. As this remains the only structurally uncharacterized lysine linkage, we comprehensively examined the structures and dynamics of K27-Ub2 using nuclear magnetic resonance, small-angle neutron scattering, and in silico ensemble modeling. Our structural data provide insights into the functional properties of K27-Ub2, in particular that K27-Ub2 may be specifically recognized by K48-selective receptor UBA2 domain from proteasomal shuttle protein hHR23a. Binding studies and mutagenesis confirmed this prediction, further highlighting structural/recognition versatility of polyubiquitins and the potential power of determining function from elucidation of conformational ensembles.

KW - Binding Sites

KW - DNA Repair Enzymes/chemistry

KW - DNA-Binding Proteins/chemistry

KW - Humans

KW - Lysine/metabolism

KW - Magnetic Resonance Spectroscopy

KW - Models, Molecular

KW - Polyubiquitin/chemistry

KW - Protein Binding

KW - Protein Conformation

KW - Scattering, Small Angle

KW - Ubiquitination

U2 - 10.1016/j.str.2016.01.007

DO - 10.1016/j.str.2016.01.007

M3 - Article

C2 - 26876099

SN - 0969-2126

VL - 24

SP - 423

EP - 436

JO - Structure

JF - Structure

IS - 3

ER -