Exploration of the TRIM fold of MuRF1 using EPR reveals a canonical antiparallel structure and extended COS-box

TY - JOUR

T1 - Exploration of the TRIM fold of MuRF1 using EPR reveals a canonical antiparallel structure and extended COS-box

AU - Stevens, Michael

AU - Franke, Barbara

AU - Skorupka, Katarzyna A.

AU - Cafiso, David S.

AU - Pornillos, Owen

AU - Mayans, Olga

AU - Norman, David G.

N1 - This research was supported by DFG SFB969, the Leducq Foundation (TNE-13CVD04), The Wellcome Trust 099149/Z/12/Z, U.S. National Institutes of Health grants R01-GM035215 and R01-GM112508, and the IMR CDT

PY - 2019/7/12

Y1 - 2019/7/12

N2 - MuRF1 (TRIM63) is a RING-type E3 ubiquitin ligase with a predicted tripartite TRIM fold. TRIM proteins rely upon the correct placement of an N-terminal RING domain, with respect to C-terminal, specific substrate-binding domains. The TRIM domain organization is orchestrated by a central helical domain that forms an antiparallel coiled-coil motif and mediates the dimerization of the fold. MuRF1 has a reduced TRIM composition characterized by a lack of specific substrate binding domains, but contains in its helical domain a conserved sequence motif termed COS-box that has been speculated to fold independently into an α-hairpin. These characteristics had led to question whether MuRF1 adopts a canonical TRIM fold. Using a combination of electron paramagnetic resonance, on spin-labeled protein, and disulfide crosslinking, we show that TRIM63 follows the structural conservation of the TRIM dimerization domain, observed in other proteins. We also show that the COS-box motif folds back onto the dimerization coiled-coil motif, predictably forming a four-helical bundle at the center of the protein and emulating the architecture of canonical TRIMs.

AB - MuRF1 (TRIM63) is a RING-type E3 ubiquitin ligase with a predicted tripartite TRIM fold. TRIM proteins rely upon the correct placement of an N-terminal RING domain, with respect to C-terminal, specific substrate-binding domains. The TRIM domain organization is orchestrated by a central helical domain that forms an antiparallel coiled-coil motif and mediates the dimerization of the fold. MuRF1 has a reduced TRIM composition characterized by a lack of specific substrate binding domains, but contains in its helical domain a conserved sequence motif termed COS-box that has been speculated to fold independently into an α-hairpin. These characteristics had led to question whether MuRF1 adopts a canonical TRIM fold. Using a combination of electron paramagnetic resonance, on spin-labeled protein, and disulfide crosslinking, we show that TRIM63 follows the structural conservation of the TRIM dimerization domain, observed in other proteins. We also show that the COS-box motif folds back onto the dimerization coiled-coil motif, predictably forming a four-helical bundle at the center of the protein and emulating the architecture of canonical TRIMs.

KW - MuRF1

KW - PELDOR

KW - TRIM fold

KW - coiled-coil

KW - disulfide cross-linking

UR - https://www.scopus.com/pages/publications/85066798666

U2 - 10.1016/j.jmb.2019.05.025

DO - 10.1016/j.jmb.2019.05.025

M3 - Article

C2 - 31125568

SN - 0022-2836

VL - 431

SP - 2900

EP - 2909

JO - Journal of Molecular Biology

JF - Journal of Molecular Biology

IS - 15

ER -