TABLE 2.

Use of synthetic chitin analogues to determine the substrate specificities of wild-type and recombinant ChiA

Strain or clone	Reaction
	p-NAGa	Substrate bound covalently to 4-MUb
		N-acetyl-α-d-glucosaminide	N-acetyl-β-d-glucosaminide	N-acetyl-β-d-galactosaminide	β-d-N,N′-diacetyl-chitobioside	β-d-N,N′,N"-triacetylchitotrioside
V. cholerae 569B	+	−	+	−	+	+
E. coli DH5αF′tet(pTDCC2)	−	−	−	−	+	+
E. coli DH5αF′tet(pTDCC2.3)	NDc	−	−	−	−	−
E. coli DH5αF′tet(pBluescriptKS+)	ND	−	−	−	−	−

^a Hydrolysis of the substrate releases a yellow pigment (61). +, yellow; −, no color change. 

^b Hydrolysis of the substrate releases 4-methylumbelliferone, which fluoresces when exposed to UV (366 nm) light (41). +, fluorescent; −, not fluorescent. 

^c ND, not done.