Solution structure of TbTFIIS2-2 PWWP domain from Trypanosoma brucei and its binding to H4K17me3 and H3K32me3

2019 ◽  
Vol 476 (2) ◽  
pp. 421-431 ◽  
Author(s):  
Rui Wang ◽  
Jie Gao ◽  
Jiahai Zhang ◽  
Xuecheng Zhang ◽  
Chao Xu ◽  
...  

Abstract Posttranslational modifications (PTMs) of core histones, such as histone methylation, play critical roles in a variety of biological processes including transcription regulation, chromatin condensation and DNA repair. In T. brucei, no domain recognizing methylated histone has been identified so far. TbTFIIS2-2, as a potential transcription elongation factors in T. brucei, contains a PWWP domain in the N-terminus which shares low sequence similarity compared with other PWWP domains and is absent from other TFIIS factors. In the present study, the solution structure of TbTFIIS2-2 PWWP domain was determined by NMR spectroscopy. TbTFIIS2-2 PWWP domain adopts a global fold containing a five-strand β-barrel and two C-terminal α-helices similar to other PWWP domains. Moreover, through systematic screening, we revealed that TbTFIIS2-2 PWWP domain is able to bind H4K17me3 and H3K32me3. Meanwhile, we identified the critical residues responsible for the binding ability of TbTFIIS2-2 PWWP domain. The conserved cage formed by the aromatic amino acids in TbTFIIS2-2 PWWP domain is essential for its binding to methylated histones.

2018 ◽  
Vol 115 (37) ◽  
pp. 9228-9233 ◽  
Author(s):  
James J. Galligan ◽  
James A. Wepy ◽  
Matthew D. Streeter ◽  
Philip J. Kingsley ◽  
Michelle M. Mitchener ◽  
...  

Histone posttranslational modifications (PTMs) regulate chromatin dynamics, DNA accessibility, and transcription to expand the genetic code. Many of these PTMs are produced through cellular metabolism to offer both feedback and feedforward regulation. Herein we describe the existence of Lys and Arg modifications on histones by a glycolytic by-product, methylglyoxal (MGO). Our data demonstrate that adduction of histones by MGO is an abundant modification, present at the same order of magnitude as Arg methylation. These modifications were detected on all four core histones at critical residues involved in both nucleosome stability and reader domain binding. In addition, MGO treatment of cells lacking the major detoxifying enzyme, glyoxalase 1, results in marked disruption of H2B acetylation and ubiquitylation without affecting H2A, H3, and H4 modifications. Using RNA sequencing, we show that MGO is capable of altering gene transcription, most notably in cells lacking GLO1. Finally, we show that the deglycase DJ-1 protects histones from adduction by MGO. Collectively, our findings demonstrate the existence of a previously undetected histone modification derived from glycolysis, which may have far-reaching implications for the control of gene expression and protein transcription linked to metabolism.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Eva Höllmüller ◽  
Simon Geigges ◽  
Marie L. Niedermeier ◽  
Kai-Michael Kammer ◽  
Simon M. Kienle ◽  
...  

AbstractDecoding the role of histone posttranslational modifications (PTMs) is key to understand the fundamental process of epigenetic regulation. This is well studied for PTMs of core histones but not for linker histone H1 in general and its ubiquitylation in particular due to a lack of proper tools. Here, we report on the chemical synthesis of site-specifically mono-ubiquitylated H1.2 and identify its ubiquitin-dependent interactome on a proteome-wide scale. We show that site-specific ubiquitylation of H1 at position K64 modulates interactions with deubiquitylating enzymes and the deacetylase SIRT1. Moreover, it affects H1-dependent chromatosome assembly and phase separation resulting in a more open chromatosome conformation generally associated with a transcriptionally active chromatin state. In summary, we propose that site-specific ubiquitylation plays a general regulatory role for linker histone H1.


2010 ◽  
Vol 401 (1) ◽  
pp. 97-114 ◽  
Author(s):  
Naoya Tochio ◽  
Takashi Umehara ◽  
Yoshiko Munemasa ◽  
Toru Suzuki ◽  
Shin Sato ◽  
...  

2005 ◽  
Vol 389 (1) ◽  
pp. 137-143 ◽  
Author(s):  
Adele M. LEHANE ◽  
Haralambos KORRES ◽  
Naresh K. VERMA

The Shigella flexneri serotypes differ in the nature of their O-antigens. The addition of glucosyl or O-acetyl groups to the common backbone repeat units gives rise to the different serotypes. GtrII glucosylates rhamnose III of the O-antigen repeat unit, thus converting serotype Y (which has no modifications to the basic O-antigen repeat unit) into serotype 2a, the most prevalent serotype. In the present study, the topology of GtrII has been determined. GtrII has nine transmembrane helices, a re-entrant loop and three large periplasmic regions. Four critical residues (Glu40, Phe414, Cys435 and Lys478) were identified in two of the periplasmic regions. Despite the lack of sequence similarity between GtrII and the Gtrs from other serotypes, three of the critical residues identified are conserved in the remaining Gtrs. This is consistent with some degree of mechanistic conservation in this functionally related group of proteins.


2015 ◽  
Vol 112 (41) ◽  
pp. E5590-E5599 ◽  
Author(s):  
Shamim Naghdi ◽  
Péter Várnai ◽  
György Hajnóczky

Voltage-dependent anion channel (VDAC) proteins are major components of the outer mitochondrial membrane. VDAC has three isoforms with >70% sequence similarity and redundant roles in metabolite and ion transport. However, only Vdac2−/− (V2−/−) mice are embryonic lethal, indicating a unique and fundamental function of VDAC2 (V2). Recently, a specific V2 requirement was demonstrated for mitochondrial Bak import and truncated Bid (tBid)-induced apoptosis. To determine the relevant domain(s) of V2 involved, VDAC1 (V1) and V2 chimeric constructs were created and used to rescue V2−/− fibroblasts. Surprisingly, the commonly cited V2-specific N-terminal extension and cysteines were found to be dispensable for Bak import and high tBid sensitivity. In gain-of-function studies, V2 (123–179) was the minimal sequence sufficient to render V1 competent to support Bak insertion. Furthermore, in loss-of-function experiments, T168 and D170 were identified as critical residues. These motifs are conserved in zebrafish V2 (zfV2) that also rescued V2-deficient fibroblasts. Because high-resolution structures of zfV2 and mammalian V1 have become available, we could superimpose these structures and recognized that the critical V2-specific residues help to create a distinctive open “pocket” on the cytoplasmic surface that could facilitate Bak recruitment.


Author(s):  
Paul B. Talbert ◽  
Steven Henikoff

Nucleosomes wrap DNA and impede access for the machinery of transcription. The core histones that constitute nucleosomes are subject to a diversity of posttranslational modifications, or marks, that impact the transcription of genes. Their functions have sometimes been difficult to infer because the enzymes that write and read them are complex, multifunctional proteins. Here, we examine the evidence for the functions of marks and argue that the major marks perform a fairly small number of roles in either promoting transcription or preventing it. Acetylations and phosphorylations on the histone core disrupt histone-DNA contacts and/or destabilize nucleosomes to promote transcription. Ubiquitylations stimulate methylations that provide a scaffold for either the formation of silencing complexes or resistance to those complexes, and carry a memory of the transcriptional state. Tail phosphorylations deconstruct silencing complexes in particular contexts. We speculate that these fairly simple roles form the basis of transcriptional regulation by histone marks. Expected final online publication date for the Annual Review of Genomics and Human Genetics Volume 22 is August 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


2019 ◽  
Author(s):  
Max A. B. Haase ◽  
David M. Truong ◽  
Jef D. Boeke

AbstractHere we report a new plasmid shuffle vector for forcing budding yeast (Saccharomyces cerevisiae) to incorporate a new genetic pathway in place of a native pathway – even essential ones – while maintaining low false positive rates (less than 1 in 108 per cell). This plasmid, dubbed “Superloser”, was designed with reduced sequence similarity to commonly used yeast plasmids (i.e. pRS400 series) to limit recombination, a process that in our experience leads to retention of the yeast gene(s) instead of the desired gene(s). In addition, Superloser utilizes two orthogonal copies of the counter-selectable marker URA3 to reduce spontaneous 5-fluoroorotic acid resistance. Finally, the CEN/ARS sequence is fused to the GAL1-10 promoter, which disrupts plasmid segregation in the presence of the sugar galactose, causing Superloser to rapidly be removed from a population of cells. We show one proof of concept shuffling experiment: swapping yeast’s core histones out for their human counterparts. Superloser is especially useful for forcing yeast to use highly unfavorable genes, such as human histones, as it enables plating a large number of cells (1.4×109) on a single 10 cm petri dish while maintaining a very low background. Therefore, Superloser is a useful tool for yeast geneticists to effectively shuffle low viability genes and/or pathways in yeast that may arise in as low as 1 in 108 cells.


2007 ◽  
Vol 293 (5) ◽  
pp. G1068-G1077 ◽  
Author(s):  
Sonoko Narisawa ◽  
Marc F. Hoylaerts ◽  
Kutbuddin S. Doctor ◽  
Michiko N. Fukuda ◽  
David H. Alpers ◽  
...  

Reexamination of the Akp3−/−mouse intestine showed that, despite the lack of intestinal alkaline phosphatase (IAP), the Akp3−/−gut still had considerable alkaline phosphatase (AP) activity in the duodenum and ileum. This activity is due to the expression of a novel murine Akp6 gene that encodes an IAP isozyme expressed in the gut in a global manner ( gIAP) as opposed to duodenum-specific IAP ( dIAP) isozyme encoded by the Akp3 gene. Phylogenetically, gIAP is similar to the rat IAP I isozyme. Kinetically, gIAP displays a 5.7-fold reduction in catalytic rate constant ( kcat) and a 30% drop in Km, leading to a 4-fold reduction kcat/ Kmcompared with dIAP, and these changes in enzymatic properties can all be attributed to a crucial R317Q substitution. Western and Northern blot analyses document the expression of Akp6 in the gut, from the duodenum to the ileum, and it is upregulated in the jejunum and ileum of Akp3−/−mice. Developmentally, Akp3 expression is turned on during postnatal days 13–15 and exclusively in the duodenum, whereas Akp6 and Akp5 are expressed from birth throughout the gut with enhanced expression at weaning. Posttranslational modifications of gIAP have a pronounced effect on its catalytic properties. Given the low catalytic efficiency of gIAP, its upregulation during fat feeding, its sequence similarity with rat IAP I, and the fact that rat IAP I has been implicated in the upregulation of surfactant-like particles during fat intake, it appears likely that gIAP may have a role in mediating the accelerated fatty acid intake observed in Akp3−/−mice fed a high-fat diet.


Author(s):  
Joachim J. Hug ◽  
Nicolas A. Frank ◽  
Christine Walt ◽  
Petra Šenica ◽  
Fabian Panter ◽  
...  

Ribosomally synthesized and post-translationally modified peptides (RiPPs) are a structurally diverse group of natural products. They feature a wide range of intriguing posttranslational modifications as exemplified by the biarylitides. These are a family of cyclic tripeptides found in Planomonospora, carrying a biaryl-linkage between two aromatic amino acids. Recent genomic analyses revealed the minimal biosynthetic prerequisite of biarylitide biosynthesis consisting of only one ribosomally synthesized pentapeptide precursor as substrate and a modifying cytochrome P450 dependent enzyme. In silico analyses revealed that the minimal biarylitide RiPP clusters are widespread among natural product producers across phylogenetic borders including myxobacteria. We report here the genome-guided discovery of the first myxobacterial biarylitide MeYLH termed Myxarylin from Pyxidicoccus fallax An d48. Myxarylin was found to be an N-methylated tripeptide surprisingly exhibiting a C–N biaryl crosslink. In contrast to Myxarylin, previously isolated biarylitides are N-acetylated tripeptides featuring a C–C biaryl crosslink. Furthermore, the formation of Myxarylin was confirmed by heterologous expression of the identified biosynthetic genes in Myxococcus xanthus DK1622. These findings expand the structural and biosynthetic scope of biarylitide type RiPPs and emphasize the distinct biochemistry found in the myxobacterial realm.


2015 ◽  
Vol 81 (8) ◽  
pp. 2910-2918 ◽  
Author(s):  
Jeella Z. Acedo ◽  
Marco J. van Belkum ◽  
Christopher T. Lohans ◽  
Ryan T. McKay ◽  
Mark Miskolzie ◽  
...  

ABSTRACTAcidocin B, a bacteriocin produced byLactobacillus acidophilusM46, was originally reported to be a linear peptide composed of 59 amino acid residues. However, its high sequence similarity to gassericin A, a circular bacteriocin fromLactobacillus gasseriLA39, suggested that acidocin B might be circular as well. Acidocin B was purified from culture supernatant by a series of hydrophobic interaction chromatographic steps. Its circular nature was ascertained by matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) mass spectrometry and tandem mass spectrometry (MS/MS) sequencing. The peptide sequence was found to consist of 58 amino acids with a molecular mass of 5,621.5 Da. The sequence of the acidocin B biosynthetic gene cluster was also determined and showed high nucleotide sequence similarity to that of gassericin A. The nuclear magnetic resonance (NMR) solution structure of acidocin B in sodium dodecyl sulfate micelles was elucidated, revealing that it is composed of four α-helices of similar length that are folded to form a compact, globular bundle with a central pore. This is a three-dimensional structure for a member of subgroup II circular bacteriocins, which are classified based on their isoelectric points of ∼7 or lower. Comparison of acidocin B with carnocyclin A, a subgroup I circular bacteriocin with four α-helices and a pI of 10, revealed differences in the overall folding. The observed variations could be attributed to inherent diversity in their physical properties, which also required the use of different solvent systems for three-dimensional structural elucidation.


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