Mee-Ngan F Yap

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We used genetic and biochemical methods to examine the genomic diversity of the enterobacterial plant pathogen Erwinia carotovora subsp. carotovora. The results obtained with each method showed that E. carotovora subsp. carotovora strains isolated from one ecological niche, potato plants, are surprisingly diverse compared to related pathogens. A comparison(More)
The recognition of a C-terminal motif in E. coli SecM ((150)FXXXXWIXXXXGIRAGP(166)) inside the ribosome tunnel causes translation arrest, but the mechanism of recognition is unknown. Whereas single mutations in this motif impair recognition, we demonstrate that new arrest-inducing peptides can be created through remodeling of the SecM C terminus. We found(More)
Enterobacterial animal pathogens exhibit aggregative multicellular behavior, which is manifested as pellicles on the culture surface and biofilms at the surface-liquid-air interface. Pellicle formation behavior requires production of extracellular polysaccharide, cellulose, and protein filaments, known as curli. Protein filaments analogous to curli are(More)
The prevailing "plug-in-the-bottle" model suggests that macrolide antibiotics inhibit translation by binding inside the ribosome tunnel and indiscriminately arresting the elongation of every nascent polypeptide after the synthesis of six to eight amino acids. To test this model, we performed a genome-wide analysis of translation in azithromycin-treated(More)
The hypersensitive response elicitor harpin (HrpN) of soft rot pathogen Erwinia chrysanthemi strains 3937 and EC16 is secreted via the type III secretion system and remains cell surface bound. Strain 3937 HrpN is essential for cell aggregation, but the C-terminal one-third of the protein is not required for aggregative activity.
HrpX/Y is a putative two-component system (TCS) encoded within the type III secretion system (T3SS) gene cluster of Dickeya dadantii. A linear regulatory cascade initiated by HrpX/Y that leads to activation of the downstream T3SS genes via HrpS and HrpL was described previously. Therefore, in D. dadantii, HrpX/Y plays an important role in regulation of(More)
The structure and expression of a senescence-associated gene (SPG31) encoding a cysteine proteinase precursor of sweet potato have been characterized. The coding region of the gene consists of two exons encoding an enzyme precursor of 341 amino acids with conserved catalytic amino acids of papain. Examination of the expression patterns of the SPG31 gene in(More)
The structure and expression of a novel senescence-associated gene (SPA15) of sweet potato were characterized. The protein coding region of the gene consists of 13 exons encoding 420 amino acids. Apparent homologues of this sweet potato gene are found in a variety of dicot and monocot plants, but not in animals or microorganisms. Examination of the(More)
In Escherichia coli, secA expression is regulated at the translational level by an upstream gene (secM) that encodes a presecretory protein. SecM contains a C-terminal sequence motif that induces a transient translation arrest. Inhibition of SecM membrane targeting prolongs the translation arrest and increases SecA synthesis by concomitantly altering the(More)