Structure and Function
Dock180 is part of a large class of proteins (GEFs) which contribute to cellular signalling events by activating small G proteins. In their resting state G proteins are bound to Guanosine diphosphate (GDP) and their activation requires the dissociation of GDP and binding of guanosine triphosphate (GTP). GEFs activate G proteins by promoting this nucleotide exchange.
Dock180 and related proteins differ from other GEFs in that they do not possess the canonical structure of tandem DH-PH domains known to elicit nucleotide exchange. Instead they possess a DHR2 domain which mediates Rac activation by stabilising it in its nucleotide-free state. Dock180-related proteins also possess a DHR1 domain which has been shown, in vitro, to bind phospholipids and which may be involved in their interaction with cellular membranes. Other structural features of Dock180 include an N-terminal SH3 domain involved in binding to ELMO proteins (see below) and a C-terminal proline-rich region which, in Myoblast city (the Drosophila melanogaster ortholog of Dock180), was shown to bind DCrk (the Drosophila ortholog of Crk).
Read more about this topic: Dock180
Famous quotes containing the words structure and function, structure and, structure and/or function:
“One theme links together these new proposals for family policy—the idea that the family is exceedingly durable. Changes in structure and function and individual roles are not to be confused with the collapse of the family. Families remain more important in the lives of children than other institutions. Family ties are stronger and more vital than many of us imagine in the perennial atmosphere of crisis surrounding the subject.”
—Joseph Featherstone (20th century)
“With sixty staring me in the face, I have developed inflammation of the sentence structure and definite hardening of the paragraphs.”
—James Thurber (1894–1961)
“A special feature of the structure of our book is the monstrous but perfectly organic part that eavesdropping plays in it.”
—Vladimir Nabokov (1899–1977)
“Philosophical questions are not by their nature insoluble. They are, indeed, radically different from scientific questions, because they concern the implications and other interrelations of ideas, not the order of physical events; their answers are interpretations instead of factual reports, and their function is to increase not our knowledge of nature, but our understanding of what we know.”
—Susanne K. Langer (1895–1985)