RAS-like GTPase Transport Protein:
This protein from M. tuberculosis is a member of the Ras
super family of proteins. Ras is involved in signal transduction
and activating mutations in human Ras are associated with many
types of cancer. While originally annotated as an arginine/ornithine
transport system ATPase, we show that the protein is most likely
a GTPase based on the compound (GDP) bound to the structure.
The structure of the GTPase domain of the protein is similar to
that of human Ras and several amino acids that line the GTP
binding pocket are conserved. Ras-like GTPases use the organic
chemical GTP (guanosine-5'-triphosphate) as a regulator of
function. During the signal transduction reaction, GTP is
converted to GDP (guanosine diphosphate). GDP is shown in the
figure bound to the active site of the M. tuberculosis
RAS-like GTPase crystal structure. Our structure is related in
sequence and structure to the methylmalonic acidemia type A
protein (PDB ID 2WWW), a protein which is responsible for a
potentially fatal metabolic disorder in humans.
For more information, please see the
Protein Data Bank entry
3md0.