8 research outputs found
Efficiency of inclusive physical education lessons for schoolchildren with minor deviations in health
The 2.2 Ă… resolution crystal structure of Bacillus cereus Nif3-family protein YqfO reveals a conserved dimetal-binding motif and a regulatory domain
YqfO of Bacillus cereus is a member of the widespread Nif3 family of proteins, which has been highlighted as an important target for structural genomics. The N- and C-terminal domains are conserved across the family and contain a dimetal-binding motif in a putative active site. YqfO contains an insert in the middle of the protein, present in a minority of bacterial family members. The structure of YqfO was determined at a resolution of 2.2 Ă… and reveals conservation of the putative active site. It also reveals the previously unknown structure of the insert, which despite extremely limited sequence conservation, bears great similarity to PII, CutA, and a number of other trimeric regulatory proteins. Our results suggest that this domain acts as a signal sensor to regulate the still-unknown catalytic activity of the more-conserved domains
Crystal Structures of YkuI and Its Complex with Second Messenger Cyclic Di-GMP Suggest Catalytic Mechanism of Phosphodiester Bond Cleavage by EAL Domains*
Cyclic di-GMP (c-di-GMP) is a ubiquitous bacterial second messenger that is
involved in the regulation of cell surface-associated traits and the
persistence of infections. Omnipresent GGDEF and EAL domains, which occur in
various combinations with regulatory domains, catalyze c-di-GMP synthesis and
degradation, respectively. The crystal structure of full-length YkuI from
Bacillus subtilis, composed of an EAL domain and a C-terminal
PAS-like domain, has been determined in its native form and in complex with
c-di-GMP and Ca2+. The EAL domain exhibits a triose-phosphate
isomerase-barrel fold with one antiparallel β-strand. The complex with
c-di-GMP-Ca2+ defines the active site of the putative
phosphodiesterase located at the C-terminal end of the β-barrel. The EAL
motif is part of the active site with Glu-33 of the motif being involved in
cation coordination. The structure of the complex allows the proposal of a
phosphodiesterase mechanism, in which the divalent cation and the general base
Glu-209 activate a catalytic water molecule for nucleophilic in-line attack on
the phosphorus. The C-terminal domain closely resembles the PAS-fold. Its
pocket-like structure could accommodate a yet unknown ligand. YkuI forms a
tight dimer via EAL-EAL and trans EAL-PAS-like domain association.
The possible regulatory significance of the EAL-EAL interface and a mechanism
for signal transduction between sensory and catalytic domains of
c-di-GMP-specific phosphodiesterases are discussed