An increasing number of surface-associated proteins identified in Gram-positive bacteria are characterized by intramolecular cross-links in structurally conserved thioester, isopeptide, and ester domains (TIE proteins). Two classes of thioester domains (TEDs) have been predicted based on sequence with, to date, only representatives of Class I structurally characterized. Here, we present crystal structures of three Class II TEDs from Bacillus anthracis, vancomycin-resistant Staphylococcus aureus, and vancomycin-resistant Enterococcus faecium. These proteins are structurally distinct from Class I TEDs due to a β-sandwich domain that is inserted into the conserved TED fold to form a slipknot structure. Further, the B. anthracis TED domain is presented in the context of a full-length sortase-anchored protein structure (BaTIE). This provides insight into the three-dimensional arrangement of TIE proteins, which emerge as very abundant putative adhesins of Gram-positive bacteria.
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http://dx.doi.org/10.1002/pro.3478 | DOI Listing |
ACS Chem Biol
January 2025
Professur Organische Chemie IV, Fakultät für Biologie, Chemie und Geowissenschaften, Department of Chemistry, Universität Bayreuth, 95447 Bayreuth, Germany.
Ketoreductases (KRs) are domains in the reductive loops of type I polyketide synthases (PKSs) and are responsible for the majority of stereocenters in reduced polyketides. Although the highly stereoselective reduction of ACP-bound β-ketothioester intermediates by KRs is crucial for the overall functioning of PKSs, the substrate-dependent stereoselectivity of KRs is a factor that is not yet fully understood, especially for KR domains in late PKS modules that act on biosynthetic precursors with complex polyketidic moieties. We present studies on the three KR domains FosKR7, PlmKR6, and EryKR6 from the biosynthetic pathways of fostriecin, phoslactomycin, and erythromycin by in vitro assays using close surrogates of the octaketidic FosKR7 biosynthetic precursor, complex derivatives and a diketide in the form of their biomimetic -acetylcysteamine thioesters.
View Article and Find Full Text PDFNucleic Acids Res
December 2024
Malopolska Centre of Biotechnology (MCB), Jagiellonian University, Gronostajowa7a, 30-387 Krakow, Poland.
Ubiquitin-related modifier 1 (Urm1) is a highly conserved member of the ubiquitin-like (UBL) family of proteins. Urm1 is a key component of the eukaryotic transfer RNA (tRNA) thiolation cascade, responsible for introducing sulfur at wobble uridine (U34) in several eukaryotic tRNAs. Urm1 must be thiocarboxylated (Urm1-SH) by its E1 activating enzyme UBL protein activator 4 (Uba4).
View Article and Find Full Text PDFNature
December 2024
Department of Biochemistry and Centre de recherche en biologie structurale, McGill University, Montréal, QC, Canada.
J Am Chem Soc
December 2024
Department of Chemistry, University of Zurich, Winterthurerstrasse 190, Zurich 8057, Switzerland.
Solid-phase peptide synthesis (SPPS) and native chemical ligation (NCL) are powerful methods for obtaining peptides and proteins that are otherwise inaccessible. Nonetheless, numerous sequences are difficult to prepare via SPPS, and cleaved peptides often have low aqueous solubility. To address these challenges, we developed a "Synthesis Tag" consisting of six arginines connected to the target sequence via a cleavable MeDbz linker.
View Article and Find Full Text PDFInsect Biochem Mol Biol
January 2025
Jiangsu Key Laboratory of Infection and Immunity, MOE Key Laboratory of Geriatric Diseases and Immunology, The Forth Affiliated Hospital of Soochow University, Institutes of Biology and Medical Sciences, Suzhou Medical College of Soochow University, Suzhou, China. Electronic address:
Disease vectors, such as arthropods, primarily rely on innate immunity to counteract pathogen invasions, typically through the recognition and binding of pathogen-associated molecular patterns (PAMPs) by the host's pattern recognition receptors (PRRs). As a conserved immune effector gene family from insects to mammals, the complement system may play an essential role in combating pathogenic microorganisms. In arthropods, the complement proteins are often referred to as thioester-containing proteins (TEPs) because thioester motifs are one of the essential functional domains of the first proteins characterized within the C3 and AM family.
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