Abstract Intrachain hydrogen bonds are a hallmark of globular proteins. Traditionally, these involve oxygen and nitrogen atoms. The electronic structure sulfur is compatible with bond formation as well. We surveyed set 85 high‐resolution protein structures in order to evaluate the prevalence geometry sulfur‐containing bonds. This information should be interest experimentalists theoreticians intersted engineering.

The spliceosomal small nuclear RNAs (snRNAs) are distributed throughout the nucleoplasm and concentrated in inclusions termed Cajal bodies (CBs). A role for CBs metabolism of snRNPs has been proposed but is not well understood. SART3/p110 protein interacts transiently with U6 U4/U6 promotes reassembly after splicing vitro. Here we report that enriched gems or residual lacking coilin. snRNP Sm-like (LSm) proteins, also involved assembly, were localized to as well. levels LSm proteins reduced...

Significance The spliceosome—the molecular particle responsible for removing interrupting sequences from eukaryotic messenger RNA—is one of the most complex cellular machines. Consisting five snRNAs and over 200 proteins in humans, its numerous changes composition shape during splicing have made it difficult to study. We characterized an algal spliceosome that is much smaller, with only 43 identifiable core proteins, majority which are essential viability other organisms. propose this highly...

The assembly of the U4 and U6 snRNPs into U4/U6 di-snRNP is necessary for pre-mRNA splicing, in Saccharomyces cerevisiae requires splicing factor Prp24. We have identified a family Prp24 homologs that includes human protein SART3/p110nrb, which had been previously as surface antigen several cancers. Sequence conservation among reveals existence fourth unidentified RNA recognition motif (RRM) Prp24, we demonstrate growth budding yeast at 37 °C. also characterized by highly conserved...

RNA ligation has been a powerful tool for incorporation of cross-linkers and nonnatural nucleotides into internal positions molecules. The most widely used method template-directed uses DNA ligase splint. While this successfully many years, it suffers from number drawbacks, principally, slow inefficient product formation release, resulting in requirement large quantities enzyme. We describe an alternative technique catalyzed by T4 instead ligase. Using splint design that allows the junction...

Abstract Insight into the dynamic properties of α‐lytic protease (αP) has been obtained through use low‐temperature X‐ray crystallography and multiple‐conformation refinement. Previous studies αLP have shown that residues around active site are able to move significantly accommodate substrates different sizes. Here we show a link between ability ligands dynamics binding pocket. Although structure at 120 K B ‐factors with uniformly low value 4.8 Å 2 for main chain, four regions stand out as...

The biotechnological uses of algae and cyanobacteria have been widely discussed in the context climate change consequent efforts to circularize economies, minimize carbon release reuse waste streams. Their great potential bioproduction bioremediation has barely exploited, particularly for well-characterized red Galdieria sulphuraria Cyanidioschyzon merolae. These other Cyanidiales are excellent candidates enhancement metabolic engineering a broad spectrum applications including production...

The spliceosome catalyzes pre-messenger RNA (pre-mRNA) splicing, an essential process in eukaryotic gene expression which non-protein-coding sequences are removed from pre-mRNA. is a large, molecular complex composed of five small nuclear RNAs (snRNAs) and over 100 proteins. Large-scale rearrangements the snRNAs their associated proteins, including changes base-pairing partners, required to properly identify intron-containing pre-mRNA, position it within spliceosome, complete cleavage...

Alternative polyadenylation (APA) is widespread among metazoans and has been shown to have important impacts on mRNA stability protein expression. Beyond a handful of well-studied organisms, however, its existence consequences not well investigated. We therefore turned the deep-branching red alga,

α-Lytic protease, a chymotrypsin-like serine is synthesized with an N-terminal 166 amino acid pro region which absolutely required for folding of the protease. The also most potent inhibitor protease known Ki ∼10-10 M. Compared to its role in reaction, relatively little about mechanism by inhibits mature While proteinaceous inhibitors generally function occluding active sites their respective targets [Bode, W., & Huber, R. (1992) Eur. J. Biochem. 204, 433−451], α-lytic dual roles and...

Proteins of the Sm and Sm-like (LSm) families, referred to collectively as (L)Sm proteins, are found in all three domains life known promote a variety RNA processes such base-pair formation, unwinding, degradation, stabilization. In eukaryotes, proteins have been studied, inter alia, for their role pre-mRNA splicing. many organisms, LSm form two distinct complexes, one consisting LSm1–7 that is involved mRNA degradation cytoplasm, other LSm2–8 binds spliceosomal U6 snRNA nucleus. We recently...

Abstract Structural and functional analysis of proteins involved in pre‐mRNA splicing is challenging because the complexity machinery, known as spliceosome. Bioinformatic, proteomic, biochemical analyses have identified a minimal spliceosome red alga Cyanidioschyzon merolae . This consists only 40 core proteins, compared to ∼70 S. cerevisiae (yeast) ∼150 humans. We report X‐ray crystallographic C. Snu13 (CmSnu13), key component assembling spliceosome, present evidence for conservation...

The Cyanidiales are a group of mostly thermophilic and acidophilic red algae that thrive near volcanic vents. Despite their phylogenetic relationship, the reduced genomes Cyanidioschyzon merolae Galdieria sulphuraria strikingly different with respect to pre-mRNA splicing, ubiquitous eukaryotic feature. Introns rare spliceosomal machinery is extremely in C. merolae, contrast G. sulphuraria. Previous studies also revealed divergent spliceosomes mesophilic alga Porphyridium purpureum algal...

U4 small nuclear RNA (snRNA) plays a fundamental role in the process of premessenger splicing, yet many questions remain regarding location, interactions, and roles its functional domains. To address some these questions, we developed first vitro reconstitution system for yeast ribonucleoproteins (snRNPs). We used this to examine domains by measuring U4/U6 base-pairing, triple-snRNP formation. In contrast previous work human extracts Xenopus oocytes, found that 3′ stem–loop is necessary...

We report on an unexpectedly high rate of unreadable chromatograms from plasmid sequencing using Beckman Coulter's protocols, chemistry, and CEQ8000 instrument. Failed or poor quality sequence were accompanied by a sharp drop, fluctuation, steady decline in the current corresponding delay signal counts beyond time capillary injection. observe correlation between presence supercoiled DNA these problems. Herein we demonstrate that sonication, which is known to fragment DNA, effective way...

Abstract Pre‐mRNA splicing is a highly conserved eukaryotic process, but our understanding of it limited by historical focus on well‐studied organisms such as humans and yeast. There considerable diversity in mechanisms components pre‐mRNA splicing, especially lineages that have evolved under the pressures genome reduction. The ancestor red algae thought to undergone reduction prior lineage's radiation, resulting overall gene intron loss extant groups. Previous studies extremophilic alga...