Structure
Across mammalian species, VMATs have been found to be structurally well conserved; VMAT1s have an overall sequence identity exceeding 80%. However, there exists only a 60% sequence identity between the human VMAT1 and VMAT2.
VMAT1 is an acidic glycoprotein with an apparent weight of 40 kDa. Although the crystallographic structure has not yet been fully resolved, VMAT1 is known to have either twelve transmembrane domains (TMDs), based on Kyte-Doolittle hydrophobicity scale analysis or ten TMDs, based on MAXHOM alignment. MAXHOM alignment was determined using the "profile-fed neural network systems from Heidelberg" (PHD) program. The main difference between these two models arises from the placement of TMDs II and IV in the vesicle lumen or the cytoplasm.
Read more about this topic: Vesicular Monoamine Transporter 1
Famous quotes containing the word structure:
“The philosopher believes that the value of his philosophy lies in its totality, in its structure: posterity discovers it in the stones with which he built and with which other structures are subsequently built that are frequently better—and so, in the fact that that structure can be demolished and yet still possess value as material.”
—Friedrich Nietzsche (1844–1900)
“Each structure and institution here was so primitive that you could at once refer it to its source; but our buildings commonly suggest neither their origin nor their purpose.”
—Henry David Thoreau (1817–1862)
“A structure becomes architectural, and not sculptural, when its elements no longer have their justification in nature.”
—Guillaume Apollinaire (1880–1918)