The structural and dynamic response of MAGI-1 PDZ1 with noncanonical domain boundaries to the binding of human papillomavirus E6.
PDZ domains are protein interaction domains that are found in cytoplasmic proteins involved in signaling pathways and subcellular transport. Their roles in the control of cell growth, cell polarity, and cell adhesion in response to cell contact render this family of proteins targets during the development of cancer. Targeting of these network hubs by the oncoprotein E6 of "high-risk" human papillomaviruses (HPVs) serves to effect the efficient disruption of cellular processes. Using NMR, we have solved the three-dimensional solution structure of an extended construct of the second PDZ domain of MAGI-1 (MAGI-1 PDZ1) alone and bound to a peptide derived from the C-terminus of HPV16 E6, and we have characterized the changes in backbone dynamics and hydrogen bonding that occur upon binding. The binding event induces quenching of high-frequency motions in the C-terminal tail of the PDZ domain, which contacts the peptide upstream of the canonical X-[T/S]-X-[L/V] binding motif. Mutations designed in the C-terminal flanking region of the PDZ domain resulted in a significant decrease in binding affinity for E6 peptides. This detailed analysis supports the notion of a global response of the PDZ domain to the binding event, with effects propagated to distal sites, and reveals unexpected roles for the sequences flanking the canonical PDZ domain boundaries.
Equipe Oncoprotéines, Ecole Supérieure de Biotechnologie de Strasbourg, Boulevard Sébastien Brant, BP 10413, 67412 Illkirch Cedex, France.
Sebastian
S
Charbonnier
Yves
Y
Nominé
Juan
J
Ramírez
Katja
K
Luck
Anne
A
Chapelle
Roland H
RH
Stote
Gilles
G
Travé
Bruno
B
Kieffer
R Andrew
RA
Atkinson
D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D015815:Cell Adhesion Molecules; D015816:Cell Adhesion Molecules, Neuronal / Q000737:chemistry* / Q000378:metabolism*; D051528:Guanylate Kinases; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D009856:Oncogene Proteins, Viral / Q000737:chemistry* / Q000378:metabolism*; D011485:Protein Binding; D011487:Protein Conformation; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D012097:Repressor Proteins / Q000737:chemistry* / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid
D048868:Adaptor Proteins, Signal Transducing; D015815:Cell Adhesion Molecules; D015816:Cell Adhesion Molecules, Neuronal; C068651:E6 protein, Human papillomavirus type 16; D009856:Oncogene Proteins, Viral; D012097:Repressor Proteins; D051528:Guanylate Kinases; C113338:MAGI1 protein, human