Anson C. K. Chan

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Campylobacter jejuni, a major cause of acute bacterial diarrhea in humans, expresses numerous proteins to import diverse forms of essential iron. The expression of p19 and an adjacent iron transporter homologue (ftr1) is strongly induced upon iron limitation, suggesting a function in iron acquisition. Here, we show that the loss of P19 alone is detrimental(More)
Helicobacter pylori and Campylobacter jejuni are human pathogens and causative agents of gastric ulcers/cancer and gastroenteritis, respectively. Recent studies have uncovered a series of proteases that are responsible for maintaining the helical shape of these organisms. The H. pylori metalloprotease Csd4 and its C. jejuni homologue Pgp1 cleave the amide(More)
In the uropathogenic Escherichia coli strain F11, in silico genome analysis revealed the dicistronic iron uptake operon fetMP, which is under iron-regulated control mediated by the Fur regulator. The expression of fetMP in a mutant strain lacking known iron uptake systems improved growth under iron depletion and increased cellular iron accumulation. FetM is(More)
Peptidoglycan modifying carboxypeptidases (CPs) are important determinants of bacterial cell shape. Here, we report crystal structures of Csd4, a three-domain protein from the human gastric pathogen Helicobacter pylori. The catalytic zinc in Csd4 is coordinated by a rare His-Glu-Gln configuration that is conserved among most Csd4 homologs, which form a(More)
Strain SYK-6 of the bacterium Sphingobium sp. catabolizes lignin-derived biphenyl via a meta-cleavage pathway. In this pathway, LigY is proposed to catalyze the hydrolysis of the meta-cleavage product (MCP) 4,11-dicarboxy-8-hydroxy-9-methoxy-2-hydroxy-6-oxo-6-phenyl-hexa-2,4-dienoate. Here, we validated this reaction by identifying 5-carboxyvanillate and(More)
Peptidoglycan (PG) modifying carboxypeptidases (CPs) are important determinants of bacterial cell shape. Here, we report crystal structures of Csd4, a threedomain protein from the human gastric pathogen Helicobacter pylori. The catalytic zinc in Csd4 is coordinated by a rare H+E+Q configuration that is conserved amongst most Csd4 homologs, which form a(More)
DNA binding by the ETS transcriptional repressor ETV6 (or TEL) is auto-inhibited ~50-fold due to an α-helix that sterically blocks its ETS domain binding interface. Using NMR spectroscopy, we demonstrate that this marginally stable helix is unfolded, and not displaced to a non-inhibitory position, when ETV6 is bound to DNA containing a consensus(More)
Campylobacter jejuni is a leading bacterial cause of food-borne illness in the developed world. Like most pathogens, C. jejuni requires iron that must be acquired from the host environment. Although the iron preference of the food-borne pathogen C. jejuni is not established, this organism possesses heme transport systems to acquire iron. ChaN is an(More)
IsdB is a receptor on the surface of the bacterial pathogen Staphylococcus aureus that extracts heme from hemoglobin (Hb) to enable growth on Hb as a sole iron source. IsdB is critically important both for in vitro growth on Hb and in infection models and is also highly upregulated in blood, serum, and tissue infection models, indicating a key role of this(More)
Protein surface layers are self-assembling, paracrystalline lattices on the surface of many prokaryotes. Surface-layer proteins have not benefited from widespread structural analysis owing to their resistance to crystallization. Here, the successful expression of a truncated version of RsaA, the surface-layer protein from Caulobacter crescentus, from a(More)
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