Sandbox Reserved 1101: Difference between revisions

====Interactions====

Different types of interactions occur between specific residues during the NTD dimerization. Asp40, Lys65, Asp39 and Glu84 residues have been identified as being particularly important.

Another intramolecular handshake interaction occurs also between <scene name='82/829354/Asp17a-asp53a_interaction/1'>Asp17 and Asp53 in subunit A</scene>. This interaction doesn’t exist in subunit B because of the orientation of subunit A with respect to subunit B, Asp17 and Asp53 are too far away in order to engage this interaction.  

These asymmetric contacts play a well-defined role in dimer formation in many species of spiders but in ''N. clavipes'' several other novel interactions occur. For example, in comparison with the ''Euprosthenops australis'' NTD, ''N. clavipes'' NTD engage more than 38,5% of novel interactions.  These ones result from the distinct topology of the three helices (H2, H3 and H5) compared to other species. Indeed, the specific angles at which the H2, H3 and H5 helices cross their counterparts in the asymmetric interface allow the correct positioning of residues and the establishment of these interactions.   

Residues T47B, M55B and K54B are more buried at the dimer interface creating specific contacts.  

<scene name='82/829354/T47b-i48a-a51a-l69a/1'>T47B engage in Van Der Waals contacts with I48A, A51A and L69A residues</scene>. Also, <scene name='82/829354/M55b-d40a-t43a/1'>M55B is commited in Van Der Waals interactions with D40A and T43A</scene>.  

K54B engage in a unique hydrogen bond to <scene name='82/829354/K54b-t43a/1'>T43A</scene> and electrostatic interaction with <scene name='82/829354/K54b-d46a/1'>D46A</scene>.