Dataset Information

Extensive proteolysis of head and inner body proteins by a morphogenetic protease in the giant Pseudomonas aeruginosa phage ?KZ.

ABSTRACT: Encased within the 280 kb genome in the capsid of the giant myovirus ?KZ is an unusual cylindrical proteinaceous 'inner body' of highly ordered structure. We present here mass spectrometry, bioinformatic and biochemical studies that reveal novel information about the ?KZ head and the complex inner body. The identification of 39 cleavage sites in 19 ?KZ head proteins indicates cleavage of many prohead proteins forms a major morphogenetic step in ?KZ head maturation. The ?KZ head protease, gp175, is newly identified here by a bioinformatics approach, as confirmed by a protein expression assay. Gp175 is distantly related to T4 gp21 and recognizes and cleaves head precursors at related but distinct S/A/G-X-E recognition sites. Within the ?KZ head there are six high-copy-number proteins that are probable major components of the inner body. The molecular weights of five of these proteins are reduced 35-65% by cleavages making their mature form similar (26-31 kDa), while their precursors are dissimilar (36-88 kDa). Together the six abundant proteins sum to the estimated mass of the inner body (15-20 MDa). The identification of these proteins is important for future studies on the composition and function of the inner body.

SUBMITTER: Thomas JA

PROVIDER: S-EPMC3323674 | biostudies-literature | 2012 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Extensive proteolysis of head and inner body proteins by a morphogenetic protease in the giant Pseudomonas aeruginosa phage φKZ.

Thomas Julie A JA Weintraub Susan T ST Wu Weimin W Winkler Dennis C DC Cheng Naiqian N Steven Alasdair C AC Black Lindsay W LW

Molecular microbiology 20120320 2

Encased within the 280 kb genome in the capsid of the giant myovirus φKZ is an unusual cylindrical proteinaceous 'inner body' of highly ordered structure. We present here mass spectrometry, bioinformatic and biochemical studies that reveal novel information about the φKZ head and the complex inner body. The identification of 39 cleavage sites in 19 φKZ head proteins indicates cleavage of many prohead proteins forms a major morphogenetic step in φKZ head maturation. The φKZ head protease, gp175, ...[more]

PMID: 22429790

Similar Datasets

Project description:The progression of cystic fibrosis (CF) from an acute to a chronic disease is often associated with the conversion of the opportunistic pathogen Pseudomonas aeruginosa from a nonmucoid form to a mucoid form in the lung. This conversion involves the constitutive synthesis of the exopolysaccharide alginate, whose production is under the control of the AlgT/U sigma factor. This factor is regulated posttranslationally by an extremely unstable process and has been commonly attributed to mutations in the algT (algU) gene. By exploiting this unstable phenotype, we isolated 34 spontaneous nonmucoid variants arising from the mucoid strain PDO300, a PAO1 derivative containing the mucA22 allele commonly found in mucoid CF isolates. Complementation analysis using a minimal tiling path cosmid library revealed that most of these mutants mapped to two protease-encoding genes, algO, also known as prc or PA3257, and mucP Interestingly, our algO mutations were complemented by both mucP and algO, leading us to delete, clone, and overexpress mucP, algO, mucE, and mucD in both wild-type PAO1 and PDO300 backgrounds to better understand the regulation of this complex regulatory mechanism. Our findings suggest that the regulatory proteases follow two pathways for regulated intramembrane proteolysis (RIP), where both the AlgO/MucP pathway and MucE/AlgW pathway are required in the wild-type strain but where the AlgO/MucP pathway can bypass the MucE/AlgW pathway in mucoid strains with membrane-associated forms of MucA with shortened C termini, such as the MucA22 variant. This work gives us a better understanding of how alginate production is regulated in the clinically important mucoid variants of Pseudomonas aeruginosaIMPORTANCE Infection by the opportunistic pathogen Pseudomonas aeruginosa is the leading cause of morbidity and mortality seen in CF patients. Poor patient prognosis correlates with the genotypic and phenotypic change of the bacteria from a typical nonmucoid to a mucoid form in the CF lung, characterized by the overproduction of alginate. The expression of this exopolysaccharide is under the control an alternate sigma factor, AlgT/U, that is regulated posttranslationally by a series of proteases. A better understanding of this regulatory phenomenon will help in the development of therapies targeting alginate production, ultimately leading to an increase in the length and quality of life for those suffering from CF.

Dataset Information

Extensive proteolysis of head and inner body proteins by a morphogenetic protease in the giant Pseudomonas aeruginosa phage ?KZ.

Publications

Extensive proteolysis of head and inner body proteins by a morphogenetic protease in the giant Pseudomonas aeruginosa phage φKZ.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets