Ian Barry Holland

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The ABC transporter HlyB is a central element of the HlyA secretion machinery, a paradigm of Type I secretion. Here, we describe the crystal structure of the HlyB-NBD (nucleotide-binding domain) with H662 replaced by Ala in complex with ATP/Mg2+. The dimer shows a composite architecture, in which two intact ATP molecules are bound at the interface of the(More)
Escherichia coli hemolysin is secreted as a water-soluble polypeptide of Mr 107,000. After binding to target erythrocytes, the membrane-bound toxin resembled an integral membrane protein in that it was refractory towards extraction with salt solutions of low ionic strength. Toxin-induced hemolysis could be totally inhibited by addition of 30 mM dextran 4(More)
The ATP-binding cassette (ABC)-transporter haemolysin (Hly)B, a central element of a Type I secretion machinery, acts in concert with two additional proteins in Escherichia coli to translocate the toxin HlyA directly from the cytoplasm to the exterior. The basic set of crystal structures necessary to describe the catalytic cycle of the isolated HlyB-NBD(More)
After optimizing the conditions, including nutrients and temperature, swarming of Bacillus subtilis 3610 was obtained on a synthetic, fully defined medium. The swarms formed highly branched (dendritic) patterns, generated by successive waves of moving cells. A detailed microscopic in situ analysis of swarms 1 and 2 revealed varied cell morphologies and a(More)
The approximately 27 kDa ABC-ATPase, an extraordinarily conserved, unique type of ATPase, acts as a machine to fuel the movement across membranes of almost any type of molecule, from large polypeptides to small ions, via many different membrane-spanning proteins. A particular ABC-ATPase must therefore be tailor-made to function in a complex with its cognate(More)
Heterologous proteins synthesized in the Gram-negative bacterium Escherichia coli in bioreactor culture may accumulate in one of three 'compartments':the cytoplasm, the periplasm, or the extracellular medium. Many overexpressed proteins from various origins have been purified from each of these locations. However, to date, each system has required specific(More)
The natural wild-type Bacillus subtilis strain 3610 swarms rapidly on the synthetic B medium in symmetrical concentric waves of branched dendritic patterns. In a comparison of the behavior of the laboratory strain 168 (trp) on different media with that of 3610, strain 168 (trp), which does not produce surfactin, displayed less swarming activity, both(More)
Haemolysin B (HlyB) is essential for secretion of the 107 x 10(3) Mr haemolysin A protein from Escherichia coli and is a member of a family of highly conserved, apparently ATP-dependent surface proteins in many organisms. We have shown in this study that both HlyB and HlyD fractionate primarily with the cytoplasmic membrane of E. coli and are accessible to(More)
Many biological processes are coupled to ATP hydrolysis. We describe here a class of closely related ATP-binding proteins, from several bacterial species, which are associated with a variety of cellular functions including membrane transport, cell division, nodulation in Rhizobium and haemolysin export. These proteins comprise a family of structurally and(More)