Journal: Nat Chem Biol / Year: 2019 Title: The morphogen Sonic hedgehog inhibits its receptor Patched by a pincer grasp mechanism. Authors: Amalie F Rudolf / Maia Kinnebrew / Christiane Kowatsch / T Bertie Ansell / Kamel El Omari / Benjamin Bishop / Els Pardon / Rebekka A Schwab / Tomas Malinauskas / Mingxing Qian / Ramona Duman ...Authors: Amalie F Rudolf / Maia Kinnebrew / Christiane Kowatsch / T Bertie Ansell / Kamel El Omari / Benjamin Bishop / Els Pardon / Rebekka A Schwab / Tomas Malinauskas / Mingxing Qian / Ramona Duman / Douglas F Covey / Jan Steyaert / Armin Wagner / Mark S P Sansom / Rajat Rohatgi / Christian Siebold / Abstract: Hedgehog (HH) ligands, classical morphogens that pattern embryonic tissues in all animals, are covalently coupled to two lipids-a palmitoyl group at the N terminus and a cholesteroyl group at the C ...Hedgehog (HH) ligands, classical morphogens that pattern embryonic tissues in all animals, are covalently coupled to two lipids-a palmitoyl group at the N terminus and a cholesteroyl group at the C terminus. While the palmitoyl group binds and inactivates Patched 1 (PTCH1), the main receptor for HH ligands, the function of the cholesterol modification has remained mysterious. Using structural and biochemical studies, along with reassessment of previous cryo-electron microscopy structures, we find that the C-terminal cholesterol attached to Sonic hedgehog (Shh) binds the first extracellular domain of PTCH1 and promotes its inactivation, thus triggering HH signaling. Molecular dynamics simulations show that this interaction leads to the closure of a tunnel through PTCH1 that serves as the putative conduit for sterol transport. Thus, Shh inactivates PTCH1 by grasping its extracellular domain with two lipidic pincers, the N-terminal palmitate and the C-terminal cholesterol, which are both inserted into the PTCH1 protein core.
Mass: 34138.750 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Details: Human PTCH1-ECD1 residues 139-423, containing three N-terminal additional residues derived from the expression vector pHLsec, and a C-terminal His6-Tag for IMAC purification. Source: (gene. exp.) Homo sapiens (human) / Gene: PTCH1, PTCH / Plasmid: pHLsec / Cell line (production host): HEK293T / Production host: Homo sapiens (human) / References: UniProt: Q13635
#2: Antibody
Llama-derivednanobodyNB64
Mass: 14043.568 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Details: Nanobody NB64 containing a C-terminal His6-Tag for purification Source: (gene. exp.) Lama glama (llama) / Plasmid: pMES4y / Production host: Escherichia coli (E. coli)
Resolution: 2.1→2.14 Å / Redundancy: 7.8 % / Mean I/σ(I) obs: 1.7 / Num. unique obs: 1068 / CC1/2: 0.521 / Rpim(I) all: 0.696 / % possible all: 75.5
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Processing
Software
Name
Version
Classification
REFMAC
5.8.0232
refinement
xia2
datareduction
Aimless
datascaling
SHELXD
phasing
Refinement
Method to determine structure: SAD / Resolution: 2.1→50 Å / Cor.coef. Fo:Fc: 0.954 / Cor.coef. Fo:Fc free: 0.934 / SU B: 5.902 / SU ML: 0.149 / Cross valid method: THROUGHOUT / ESU R: 0.235 / ESU R Free: 0.196 / Details: HYDROGENS HAVE BEEN ADDED IN THE RIDING POSITIONS
Rfactor
Num. reflection
% reflection
Selection details
Rfree
0.25498
1372
5 %
RANDOM
Rwork
0.21577
-
-
-
obs
0.21771
25995
95.91 %
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Solvent computation
Ion probe radii: 0.8 Å / Shrinkage radii: 0.8 Å / VDW probe radii: 1.2 Å