title: Polynucleotide Phosphorylase, RNase E/G, and YbeY Are Involved in the Maturation of 4.5S RNA in Corynebacterium glutamicum.
abstract: Corynebacterium glutamicumhas been applied for the industrial production of various metabolites, such as amino acids. To understand the biosynthesis of the membrane protein in this bacterium, we investigated the process of signal recognition particle (SRP) assembly. SRP is found in all three domains of life and plays an important role in the membrane insertion of proteins. SRP RNA is initially transcribed as precursor molecules; however, relatively little is known about its maturation. InC. glutamicum, SRP consists of the Ffh protein and 4.5S RNA lacking an Alu domain. In this study, we found that 3'-to-5' exoribonuclease, polynucleotide phosphorylase (PNPase), and two endo-type RNases, RNase E/G and YbeY, are involved in the 3' maturation of 4.5S RNA inC. glutamicumThe mature form of 4.5S RNA was inefficiently formed in ΔrneGΔpnpmutant cells, suggesting the existence of an alternative pathway for the 3' maturation of 4.5S RNA. Primer extension analysis also revealed that the 5' mature end of 4.5S RNA corresponds to that of the transcriptional start site. Immunoprecipitated Ffh protein contained immature 4.5S RNA in Δpnp, ΔrneG, and ΔybeYmutants, suggesting that 4.5S RNA precursors can interact with Ffh. These results imply that the maturation of 4.5S RNA can be performed in the 4.5S RNA-Ffh complex.IMPORTANCEOverproduction of a membrane protein, such as a transporter, is useful for engineering of strains ofCorynebacterium glutamicum, which is a workhorse of amino acid production. To understand membrane protein biogenesis in this bacterium, we investigated the process of signal recognition particle (SRP) assembly. SRP contains the Ffh protein and SRP RNA and plays an important role in the membrane insertion of proteins. Although SRP RNA is highly conserved among the three domains of life, relatively little is known about its maturation. We show that PNPase, RNase E/G, and YbeY are involved in the 3' maturation of the SRP RNA (4.5S RNA) in this bacterium. This indicates that 3' end processing in this organism is different from that in other bacteria, such asEscherichia coli.
authors.affiliation: Research Institute of Innovative Technology for the Earth, Kyoto, Japan.|Department of Bioengineering, Tokyo Institute of Technology, Yokohama, Japan.
authors.forename: Tomoya
authors.initials: T
authors.lastname: Maeda
authors.affiliation: Research Institute of Innovative Technology for the Earth, Kyoto, Japan.
authors.forename: Yuya
authors.initials: Y
authors.lastname: Tanaka
authors.affiliation: Department of Bioengineering, Tokyo Institute of Technology, Yokohama, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Wachi
authors.affiliation: Research Institute of Innovative Technology for the Earth, Kyoto, Japan mmg-lab@rite.or.jp.|Graduate School of Biological Sciences, Nara Institute of Science and Technology, Nara, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Inui
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D048230:Corynebacterium glutamicum / Q000235:genetics / Q000378:metabolism*; D004722:Endoribonucleases / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D005838:Genotype; D008667:Metalloproteins / Q000235:genetics / Q000378:metabolism*; D011117:Polyribonucleotide Nucleotidyltransferase / Q000235:genetics / Q000378:metabolism*; D012329:RNA, Bacterial / Q000235:genetics / Q000378:metabolism*
chemical_list: C409968:4.5S RNA; D001426:Bacterial Proteins; D008667:Metalloproteins; D012329:RNA, Bacterial; D011117:Polyribonucleotide Nucleotidyltransferase; D004722:Endoribonucleases
keywords: Corynebacterium glutamicum; PNPase; RNA processing; RNase E/G; YbeY; signal recognition particle (SRP)