SPSY rabbit pAb

catalytic activity:S-adenosylmethioninamine + spermidine = 5'-methylthioadenosine + spermine.,disease:Defects in SMS are the cause of Snyder-Robinson syndrome (SRS) [MIM:309583]; also called X-linked mental retardation Snyder-Robinson type. SRS is characterized by moderate intellectual deficit, hypotonia, an unsteady gait, osteoporosis, kyphoscoliosis and facial asymmetry. Transmission is X-linked recessive.,domain:Composed of 3 domains: the N-terminal domain has structural similarity to S-adenosylmethionine decarboxylase, the central domain is made up of four beta strands and the C-terminal domain is similar in structure to spermidine synthase. The N- and C-terminal domains are both required for activity.,function:Required for normal viability, growth and fertility.,pathway:Amine and polyamine biosynthesis; spermine biosynthesis; spermine from spermidine: step 1/1.,similarity:Belongs to the spermidine/spermine synthase family.,subunit:Homodimer. Dimerization is mediated through the N-terminal domain and seems to be required for activity as deletion of the N-terminal domain causes complete loss of activity.,