Structural model of the hUbA1-UbcH10 quaternary complex: in silico and experimental analysis of the protein-protein interactions between E1, E2 and ubiquitin.
UbcH10 is a component of the Ubiquitin Conjugation Enzymes (Ubc; E2) involved in the ubiquitination cascade controlling the cell cycle progression, whereby ubiquitin, activated by E1, is transferred through E2 to the target protein with the involvement of E3 enzymes. In this work we propose the first three dimensional model of the tetrameric complex formed by the human UbA1 (E1), two ubiquitin molecules and UbcH10 (E2), leading to the transthiolation reaction. The 3D model was built up by using an experimentally guided incremental docking strategy that combined homology modeling, protein-protein docking and refinement by means of molecular dynamics simulations. The structural features of the in silico model allowed us to identify the regions that mediate the recognition between the interacting proteins, revealing the active role of the ubiquitin crosslinked to E1 in the complex formation. Finally, the role of these regions involved in the E1-E2 binding was validated by designing short peptides that specifically interfere with the binding of UbcH10, thus supporting the reliability of the proposed model and representing valuable scaffolds for the design of peptidomimetic compounds that can bind selectively to Ubcs and inhibit the ubiquitylation process in pathological disorders.
Kedrion S.p.A., Sant 'Antimo (Na), Italy.
Stefania
S
Correale
Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche, Napoli, Italy.
Ivan
I
de Paola
Dipartimento di Farmacia, Università degli Studi di Napoli Federico II, Napoli, Italy.
Carmine Marco
CM
Morgillo
Istituto di Endocrinologia ed Oncologia Sperimentale Consiglio Nazionale delle Ricerche, Napoli, Italy.
Antonella
A
Federico
Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche, Napoli, Italy.
Laura
L
Zaccaro
Istituto di Endocrinologia ed Oncologia Sperimentale Consiglio Nazionale delle Ricerche, Napoli, Italy.
Pierlorenzo
P
Pallante
Dipartimento di Farmacia, Università degli Studi di Napoli Federico II, Napoli, Italy.
Aldo
A
Galeone
Istituto di Endocrinologia ed Oncologia Sperimentale Consiglio Nazionale delle Ricerche, Napoli, Italy.
Alfredo
A
Fusco
Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche, Napoli, Italy.
Emilia
E
Pedone
Departament de Fisicoquímica and Institut de Biomedicina (IBUB), Facultat de Farmàcia, Universitat de Barcelona, Santa Coloma de Gramenet, Spain.
F Javier
FJ
Luque
Dipartimento di Farmacia, Università degli Studi di Napoli Federico II, Napoli, Italy.
Bruno
B
Catalanotti
D001665:Binding Sites; D003198:Computer Simulation; D018360:Crystallography, X-Ray; D006801:Humans; D008958:Models, Molecular; D009097:Multienzyme Complexes / Q000737:chemistry*; D020836:Protein Structure, Quaternary; D025801:Ubiquitin / Q000378:metabolism*; D044764:Ubiquitin-Activating Enzymes / Q000737:chemistry* / Q000378:metabolism; D044763:Ubiquitin-Conjugating Enzymes / Q000737:chemistry* / Q000378:metabolism
D009097:Multienzyme Complexes; C471538:UBA1 protein, human; D025801:Ubiquitin; C105156:UBE2C protein, human; D044763:Ubiquitin-Conjugating Enzymes; D044764:Ubiquitin-Activating Enzymes