Figure 1 . (a) The lipoylation process of H protein in E.
coli and the shuttling role of lipoylated H protein in the glycine
cleavage system. LplA catalyzes the lipoylation process in two steps: 1.
Adenylation of lipoic acid, and 2. lipoate transfer to H protein(Morris
et al. 1995). (b) Main conformational changes of LplA during the
lipoylation process. LplA contains a N-terminal domain and a movable
C-terminal domain. The latter rotates from a bending (closed)
conformation to a stretched (open) conformation upon binding of lipoate
and ATP and probably under the effect of Hapo (Fujiwara
et al. 1991). Key secondary structures of the C-terminus are indicated
by colors: β-12 in yellow, β-13 in orange, β-14 in red, α-8 in magenta,
α-9 in blue, α-10 in beige.