title: Mutagenic Analysis of the C-Terminal Extension of Lsm1.
abstract: The Sm-like proteins (also known as Lsm proteins) are ubiquitous in nature and exist as hexa or heptameric RNA binding complexes. They are characterized by the presence of the Sm-domain. The Lsm1 through Lsm7 proteins are highly conserved in eukaryotes and they form a hetero-octameric complex together with the protein Pat1. The Lsm1-7-Pat1 complex plays a key role in mRNA decapping and 3'-end protection and therefore is required for normal mRNA decay rates in vivo. Lsm1 is a key subunit that is critical for the unique RNA binding properties of this complex. We showed earlier that unlike most Sm-like proteins, Lsm1 uniquely requires both its Sm domain and its C-terminal extension to contribute to the function of the Lsm1-7-Pat1 complex and that the C-terminal segment can associate with the rest of the complex and support the function even in trans. The studies presented here identify a set of residues at the very C-terminal end of Lsm1 to be functionally important and suggest that these residues support the function of the Lsm1-7-Pat1 complex by facilitating RNA binding either directly or indirectly.
authors.affiliation: Department of Biochemistry, Uniformed Services University of the Health Sciences (USUHS), 4301, Jones Bridge Road, Bethesda, MD, 20814-4799, United States of America.
authors.forename: Ashis
authors.initials: A
authors.lastname: Chowdhury
authors.affiliation: Department of Biochemistry, Uniformed Services University of the Health Sciences (USUHS), 4301, Jones Bridge Road, Bethesda, MD, 20814-4799, United States of America.
authors.forename: Swathi
authors.initials: S
authors.lastname: Kalurupalle
authors.affiliation: Department of Biochemistry, Uniformed Services University of the Health Sciences (USUHS), 4301, Jones Bridge Road, Bethesda, MD, 20814-4799, United States of America.
authors.forename: Sundaresan
authors.initials: S
authors.lastname: Tharun
mesh_terms: D006801:Humans; D008968:Molecular Conformation; D046912:Multiprotein Complexes / Q000737:chemistry / Q000235:genetics; D016296:Mutagenesis / Q000235:genetics*; D009154:Mutation / Q000235:genetics; D009691:Nucleic Acid Denaturation / Q000235:genetics; D011485:Protein Binding; D039381:RNA Cap-Binding Proteins / Q000737:chemistry* / Q000235:genetics; D020871:RNA Stability; D016601:RNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics
chemical_list: C114069:LSM1 protein, S cerevisiae; D046912:Multiprotein Complexes; C103266:PAT1 protein, S cerevisiae; D039381:RNA Cap-Binding Proteins; D016601:RNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins