We have characterized the yyaA gene of Bacillus subtilis, located near the origin of chromosome replication (oriC). Its protein product is similar to the Spo0J protein, which belongs to the ParB family of chromosome- and plasmid-partitioning proteins. Insertional inactivation of the yyaA gene had no apparent effect on chromosome organization and partitioning during vegetative growth or sporulation. Subcellular localization of YyaA by immunofluorescence microscopy indicated that it colocalizes with the nucleoid, and gel retardation studies confirmed that YyaA binds relatively nonspecifically to DNA. Overexpression of yyaA caused a sporulation defect characterized by the formation of multiple septa within the cell. This phenotype indicates that YyaA may have a regulatory role at the onset of sporulation.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC134793 | PMC |
http://dx.doi.org/10.1128/jb.184.4.1102-1111.2002 | DOI Listing |
J Immunol
September 2014
Division of Immune Cell Biology, Medical Research Council National Institute for Medical Research, London NW7 1AA, United Kingdom; and
Survival of naive T cells requires engagement of TCR with self-peptide major histocompatibility Ags. The signaling pathways required to transmit this survival signal are poorly understood. In this study, we asked whether the tyrosine kinase Zap70 is required to transmit survival signals in naive CD8 T cells.
View Article and Find Full Text PDFJ Exp Med
October 2009
Department of Medicine, Rosalind Russell Medical Research Center for Arthritis, Howard Hughes Medical Institute, University of California San Francisco Children's Hospital, University of California, San Francisco, San Francisco, CA 94143, USA.
ZAP-70 is critical for T cell receptor (TCR) signaling. Tyrosine to phenylalanine mutations of Y315 and Y319 in ZAP-70 suggest these residues function to recruit downstream effector molecules, but mutagenesis and crystallization studies reveal that these residues also play an important role in autoinhibition ZAP-70. To address the importance of the scaffolding function, we generated a zap70 mutant mouse (YYAA mouse) with Y315 and Y319 both mutated to alanines.
View Article and Find Full Text PDFMicrobiology (Reading)
April 2006
Department of Bioinformatics and Genomics, Graduate School of Information Science, Nara Institute of Science and Technology (NAIST), 8916-5, Takayama, Ikoma, Nara 630-0101, Japan.
Previous work has shown that the Bacillus subtilis EzrA protein directly inhibits FtsZ ring assembly, which is required for normal cell division, and that loss of EzrA results in hyperstabilization of the FtsZ polymer in vivo. Here, it was found that in ezrA-disrupted cells, artificial expression of YneA, which suppresses cell division during the SOS response, and disruption of noc (yyaA), which acts as an effector of nucleoid occlusion, resulted in accumulation of multiple non-constricting FtsZ rings, inhibition of cell division, and synthetic lethality. Overexpression of the essential cell division protein FtsL suppressed the effect of ezrA disruption.
View Article and Find Full Text PDFCell
June 2004
Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom.
A range of genetical and physiological experiments have established that diverse bacterial cells possess a function called nucleoid occlusion, which acts to prevent cell division in the vicinity of the nucleoid. We have identified a specific effector of nucleoid occlusion in Bacillus subtilis, Noc (YyaA), as an inhibitor of division that is also a nonspecific DNA binding protein. Under various conditions in which the cell cycle is perturbed, Noc prevents the division machinery from assembling in the vicinity of the nucleoid.
View Article and Find Full Text PDFJ Bacteriol
February 2002
Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom.
We have characterized the yyaA gene of Bacillus subtilis, located near the origin of chromosome replication (oriC). Its protein product is similar to the Spo0J protein, which belongs to the ParB family of chromosome- and plasmid-partitioning proteins. Insertional inactivation of the yyaA gene had no apparent effect on chromosome organization and partitioning during vegetative growth or sporulation.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!