ID 2.5.1.79 DE thermospermine synthase. CA S-adenosyl 3-(methylsulfanyl)propylamine + spermidine = H(+) + S-methyl- CA 5'-thioadenosine + thermospermine. CC -!- This enzyme is required for correct xylem specification through CC regulation of the lifetime of the xylem elements. DR Q9S7X6, ACL5_ARATH ; A2BIX4, SPEE1_HYPBU; P09158, SPEE_ECOLI ; DR Q8ZXM4, SPEE_PYRAE ; Q9UXE4, SPEE_SACS2 ; Q5SK28, SPEE_THET8 ; //