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Figure 3.
Figure 3 Contacts between the relay region, converter domain and
lever arm helix allow these structural elements to move
together. (A) The relay region and SH1 helix of MyoE are shown
in cyan. In MyoE and other class-I myosins, there is a hydrogen
bond between Thr418 in the relay helix and Asn618 from the SH1
helix. (B) Close-up view of this region, viewed along the relay
helix. The kink forms at Thr418. (C) Highly conserved residues
form a hydrophobic core, and polar residues further stabilize
the link via conserved hydrogen bonds (dashed lines). This core
interaction is further supported by a small, hydrophobic, highly
conserved extension into the converter formed by residues Tyr630
and Val677 (DdTyr699 and DdIle744). At the tip of the relay loop
(cyan), conserved Glu429 (DdGlu497) forms hydrogen bonds to
residue Thr675 of the converter domain (brown) (DdThr742; at
this position there is always a threonine or a serine) and to
the backbone nitrogen atoms of converter residues Lys674 and
Lys676. (D) Hydrophobic interactions between the lever arm helix
(cyan) and core domain (white). All class-I myosins contain an
aromatic residue at the positions of Tyr69 and/or Tyr71 (red) in
close contact with the conserved Phe686 (red) in the lever arm
helix. Either a glycine or an alanine is found at the equivalent
position to Phe686 in class-II myosins.
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