a mild proteolytic treatment of the dimeric beta 2 subunit of escherichia coli tryptophan synthetase ( l-serine hydrolase ( adding indole ) ec 4.2.1.20 ) is known to nick each polypeptide chain into two complementary fragments , f1 and f2 ( hogberg-railbaud , a. , and goldberg , m.e . ( 1977 ) proc . natl . acad . sci . u.s.a. 74 , 442-446 ) .
C0597304
proteolytic
C1418943
proc