Table 1.

Kinetic constants and apparent specificity constants for FimD-catalyzed assembly of FimC-subunit complexes at pH 8.0

FimD substrate	kon (M−1 s−1)a	koff (s−1)a	kDSE (s−1)b	$K_{\mathrm{M}}^{\mathrm{app}}$$\left(=\frac{k_{\mathrm{off}}+k_{\mathrm{DSE}}}{k_{\mathrm{on}}}\right)\left(\mathrm{\mu }\mathrm{M}\right)$	$k_{\mathrm{DSE}}/K_{\mathrm{M}}^{\mathrm{app}}\left({\mathrm{M}}^{-1}{\mathrm{s}}^{-1}\right)$	$\frac{k_{\mathrm{DSE}}/K_{\mathrm{M}}^{\mathrm{app}}}{k_{\mathrm{DSE}}/K_{\mathrm{M}}^{\mathrm{app}}\left(\mathrm{FimCI}\right)}$
FimCI	1.45 · 108	94	0.14 (I-A)	0.65	2.2 · 105	1.0
FimCG	2.85 · 107	855	2.85 (G-H)	30.1	9.5 · 104	0.44
FimCA	1.1 · 107	267	1.4 (A-A)	24.4	5.7 · 104	0.27
FimCF	1.8 · 107	142	0.053 (F-G)	7.9	6.7 · 103	3.1 · 10−2
FimCA	1.1 · 107	267	0.0055 (A-F)	24.3	2.3 · 102	1.1 · 10−3

^ak_on and k_off values refer to binding of FimC-subunit complexes to FimD_N. Values for FimCG were taken from⁴⁹, values for FimCA and FimCF from²⁰.

^bk_DSE values refer to formation of preferred subunit-subunit contacts, i.e., incorporation of FimG into FimH (G-H), FimF into FimG (F-G), FimA into FimF (A-F), FimA into FimA (A-A) and FimI into FimA (I-A).