Single-molecule study on histone-like nucleoid-structuring protein (H-NS) paralogue in Pseudomonas aeruginosa: MvaU bears DNA organization mode similarities to MvaT.
Pseudomonas aeruginosa contains two distinct members of H-NS family of nucleoid-structuring proteins: MvaT and MvaU. Together, these proteins bind to the same regions of the chromosome and function coordinately in the regulation of hundreds of genes. Due to their structural similarity, they can associate to form heteromeric complexes. These findings left us wondering whether they bear similar DNA binding properties that underlie their gene-silencing functions. Using single-molecule stretching and imaging experiments, we found striking similarities in the DNA organization modes of MvaU compared to the previously studied MvaT. MvaU can form protective nucleoprotein filaments that are insensitive to environmental factors, consistent with its role as a repressor of gene expression. Similar to MvaT, MvaU filament can mediate DNA bridging while excessive MvaU can cause DNA aggregation. The almost identical DNA organization modes of MvaU and MvaT explain their functional redundancy, and raise an interesting question regarding the evolutionary benefits of having multiple H-NS paralogues in the Pseudomonas genus.
NUS Graduate school for Integrative Sciences and Engineering, Singapore, Singapore; Mechanobiology Institute, National University of Singapore, Singapore, Singapore; Centre for Bioimaging Sciences, National University of Singapore, Singapore, Singapore.
Ricksen S
RS
Winardhi
Division of Infectious Diseases, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America.
Sandra
S
Castang
Division of Infectious Diseases, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America.
Simon L
SL
Dove
Mechanobiology Institute, National University of Singapore, Singapore, Singapore; Centre for Bioimaging Sciences, National University of Singapore, Singapore, Singapore; Department of Physics, National University of Singapore, Singapore, Singapore.
Jie
J
Yan
D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D004269:DNA, Bacterial / Q000737:chemistry* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D020868:Gene Silencing; D011550:Pseudomonas aeruginosa / Q000737:chemistry* / Q000378:metabolism; D012097:Repressor Proteins / Q000737:chemistry* / Q000378:metabolism
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D012097:Repressor Proteins