Question

What are the domains of an HSP-40 (DNAJ)? What do they bind? What form does it take, and which is the most highly conserved?

A) A and B Domains, Bind RNA, Helical Form, C Domain
B) J and C Domains, Bind Proteins, Sheet Form, J Domain
C) X and Y Domains, Bind Lipids, Spherical Form, Y Domain
D) H and S Domains, Bind Nucleotides, Tubular Form, S Domain

Answer 1

HSP-40 (DNAJ proteins) have J and C domains, with the J-domain being the most conserved and responsible for binding to proteins, particularly HSP-70, aiding in protein folding.

Step-by-step explanation:

The domains of HSP-40 (DNAJ proteins) are the J-domain, which is highly conserved, and the C-domain. The J-domain binds proteins, not RNA, and is essential for the interaction with HSP-70. The form taken up by these proteins isn't strictly defined as helical or sheet but can contain elements of both, with the J-domain being particularly characterized by a His-Pro-Asp (HPD) motif critical for interaction with HSP-70's ATPase domain. The C-domain, while less conserved, also contributes to the protein's function, often mediating binding to client proteins and contributing to the overall structure of HSP-40.