Dataset Information

Co-evolution of multipartite interactions between an extended tmRNA tag and a robust Lon protease in Mycoplasma.

ABSTRACT: Messenger RNAs that lack in-frame stop codons promote ribosome stalling and accumulation of aberrant and potentially harmful polypeptides. The SmpB-tmRNA quality control system has evolved to solve problems associated with non-stop mRNAs, by rescuing stalled ribosomes and directing the addition of a peptide tag to the C-termini of the associated proteins, marking them for proteolysis. In Escherichia coli, the ClpXP system is the major contributor to disposal of tmRNA-tagged proteins. We have shown that the AAA+ Lon protease can also degrade tmRNA-tagged proteins, but with much lower efficiency. Here, we present a unique case of enhanced recognition and degradation of an extended Mycoplasma pneumoniae (MP) tmRNA tag by the MP-Lon protease. We demonstrate that MP-Lon can efficiently and selectively degrade MP-tmRNA-tagged proteins. Most significantly, our studies reveal that the larger (27 amino acids long) MP-tmRNA tag contains multiple discrete signalling motifs for efficient recognition and rapid degradation by Lon. We propose that higher-affinity multipartite interactions between MP-Lon and the extended MP-tmRNA tag have co-evolved from pre-existing weaker interactions, as exhibited by Lon in E. coli, to better fulfil the function of MP-Lon as the sole soluble cytoplasmic protease responsible for the degradation of tmRNA-tagged proteins.

SUBMITTER: Ge Z

PROVIDER: S-EPMC2806816 | biostudies-literature | 2009 Dec

REPOSITORIES: biostudies-literature

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Co-evolution of multipartite interactions between an extended tmRNA tag and a robust Lon protease in Mycoplasma.

Ge Zhiyun Z Karzai A Wali AW

Molecular microbiology 20091113 5

Messenger RNAs that lack in-frame stop codons promote ribosome stalling and accumulation of aberrant and potentially harmful polypeptides. The SmpB-tmRNA quality control system has evolved to solve problems associated with non-stop mRNAs, by rescuing stalled ribosomes and directing the addition of a peptide tag to the C-termini of the associated proteins, marking them for proteolysis. In Escherichia coli, the ClpXP system is the major contributor to disposal of tmRNA-tagged proteins. We have sho ...[more]

PMID: 19912542

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Project description:Acinetobacter baumannii is a Gram-negative opportunistic pathogen that is known to survive harsh environmental conditions and is a leading cause of hospital-acquired infections. Specifically, multicellular communities (known as biofilms) of A. baumannii can withstand desiccation and survive on hospital surfaces and equipment. Biofilms are bacteria embedded in a self-produced extracellular matrix composed of proteins, sugars, and/or DNA. Bacteria in a biofilm are protected from environmental stresses, including antibiotics, which provides the bacteria with selective advantage for survival. Although some gene products are known to play roles in this developmental process in A. baumannii, mechanisms and signaling remain mostly unknown. Here, we find that Lon protease in A. baumannii affects biofilm development and has other important physiological roles, including motility and the cell envelope. Lon proteases are found in all domains of life, participating in regulatory processes and maintaining cellular homeostasis. These data reveal the importance of Lon protease in influencing key A. baumannii processes to survive stress and to maintain viability.IMPORTANCE Acinetobacter baumannii is an opportunistic pathogen and is a leading cause of hospital-acquired infections. A. baumannii is difficult to eradicate and to manage, because this bacterium is known to robustly survive desiccation and to quickly gain antibiotic resistance. We sought to investigate biofilm formation in A. baumannii, since much remains unknown about biofilm formation in this bacterium. Biofilms, which are multicellular communities of bacteria, are surface attached and difficult to eliminate from hospital equipment and implanted devices. Our research identifies multifaceted physiological roles for the conserved bacterial protease Lon in A. baumannii These roles include biofilm formation, motility, and viability. This work broadly affects and expands understanding of the biology of A. baumannii, which will permit us to find effective ways to eliminate the bacterium.

Dataset Information

Co-evolution of multipartite interactions between an extended tmRNA tag and a robust Lon protease in Mycoplasma.

Publications

Co-evolution of multipartite interactions between an extended tmRNA tag and a robust Lon protease in Mycoplasma.

Similar Datasets

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