<p>This group consists of bacterial proteins, which contain a P-loop. They are probably essential to bacteria as members are found in all genomes so far sequenced and no equivalent genes have been found in the archaea and eukaryotes, suggesting the protein may be involved in cell wall biosynthesis. The sequence of YjeE, from <taxon tax_id="727">Haemophilus influenzae</taxon>, has been determined to 1.7-A resolution. The protein has a nucleotide-binding fold with a four-stranded parallel beta-sheet flanked by antiparallel beta-strands on each side. The topology of the beta-sheet is unique among P-loop proteins and has features of different families of enzymes. ADP has been shown to bind to the P-loop in the presence of Mg2+ and ATPase activity has been confirmed by kinetic measurements [<cite idref="PUB00016159"/>].</p> Uncharacterised domain UPF0079, ATPase bacteria