• Title/Summary/Keyword: N-terminal domain

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The Receptor-Ligand Interaction Revealed by a Homology Modelling of the Receptor Binding Domain of Human Thrombopoietin

  • Song, Jin-Soo;Park, Heung-Rok;Hong, Hyo-Jeong;Yu, Myeong-Hee;Ryu, Seong-Eon
    • Proceedings of the Korean Biophysical Society Conference
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    • 1997.07a
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    • pp.43-43
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    • 1997
  • Platelet production in blood is regulated by a lineage specific humoral factor called thrombopoietin (TPO). The amino terminal domain of TPO (TPO-N) has a sequence homology to erythropoietin (EPO) and is responsible for the signal transduction mediated by the TPO receptor, c-mpl.(omitted)

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Prostaglandin E Synthase, a Terminal Enzyme for Prostaglandin E2 Biosynthesis

  • Kudo, Ichiro;Murakami, Makoto
    • BMB Reports
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    • v.38 no.6
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    • pp.633-638
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    • 2005
  • Biosynthesis of prostanoids is regulated by three sequential enzymatic steps, namely phospholipase $A_2$ enzymes, cyclooxygenase (COX) enzymes, and various lineage-specific terminal prostanoid synthases. Prostaglandin E synthase (PGES), which isomerizes COX-derived $PGH_2$ specifically to $PGE_2$, occurs in multiple forms with distinct enzymatic properties, expressions, localizations and functions. Two of them are membrane-bound enzymes and have been designated as mPGES-1 and mPGES-2. mPGES-1 is a perinuclear protein that is markedly induced by proinflammatory stimuli, is down-regulated by anti inflammatory glucocorticoids, and is functionally coupled with COX-2 in marked preference to COX-1. Recent gene targeting studies of mPGES-1 have revealed that this enzyme represents a novel target for anti-inflammatory and anti-cancer drugs. mPGES-2 is synthesized as a Golgi membrane-associated protein, and the proteolytic removal of the N-terminal hydrophobic domain leads to the formation of a mature cytosolic enzyme. This enzyme is rather constitutively expressed in various cells and tissues and is functionally coupled with both COX-1 and COX-2. Cytosolic PGES (cPGES) is constitutively expressed in a wide variety of cells and is functionally linked to COX-1 to promote immediate $PGE_2$ production. This review highlights the latest understanding of the expression, regulation and functions of these three PGES enzymes.

Molecular Characterization of AceB, a Gene Encoding Malate Synthase in Corynebacterium glutamicum

  • Lee, Heung-Shick;Anthony J. Sinskey
    • Journal of Microbiology and Biotechnology
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    • v.4 no.4
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    • pp.256-263
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    • 1994
  • The aceB gene, encoding for malate synthase, one of the key enzymes of glyoxylate bypass, was isolated from a pMT1-based Corynebacterium glutamicum gene library via complementation of an Escherichia coli aceB mutant on an acetate minimal medium. The aceB gene was closely linked to aceA, separated by 598 base pairs, and transcribed in divergent direction. The aceB expressed a protein product of Mr 83, 000 in Corynebacterium glutamicum which was unusually large compared with those of other malate synthases. A DNA-sequence analysis of the cloned DNA identified an open-reading frame of 2, 217 base pairs which encodes a protein with the molecular weight of 82, 311 comprising 739 aminoo acids. The putative protein product showed only limited amino acid-sequence homology to its counteliparts in other organisms. The N-terminal region of the protein, which shows no apparent homology with the known sequences of other malate synthases, appeared to be responsible for the protein s unusually large size. A potential calciumbinding domain of EF-hand structure found among eukaryotes was detected in the N-terminal region of the deduced protein.

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Generation and Expression of Amino-Terminal Domain of the Gene Coding for the Lumazine Protein from Photobacterium phosphoreum (발광 박테리아 Photobacterium phosphoreum의 Lumazine Protein을 코드 하는 유전자의 염기 서열 분석 및 발현)

  • Woo Young-Eun;Kim So-Young;Lee Chan-Yong
    • Korean Journal of Microbiology
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    • v.41 no.4
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    • pp.306-311
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    • 2005
  • In this study, the amino-terminal half truncated lump and the whole lump genes from Photobacterium phosphoreum coding for the lumazine protein were cloned by polymerase chain reaction and expressed in Escherichia coli. To identifiy of the binding site of the ligand or substrate, the amino acid identities from the sequences of the lumazine protein, yellow fluorescent protein, and riboflavin synthase from different organisms were also compared and analyzed.

Molecular Genetic Characterization and Analysis of Glucocorticoid Receptor Expression in the Big-belly Seahorse Hippocampus abdominalis (빅벨리해마(Hippocampus abdominalis) 글루코코르티코이드 수용체의 분자 유전학적 동정과 발현 분석)

  • Jo, Eunyoung;Oh, Minyoung;Lee, Sukkung;Qiang, Wan;Lee, Jehee
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.48 no.3
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    • pp.346-353
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    • 2015
  • Glucocorticoids (GCs) are steroid hormones regulated through responses to stress to maintain diverse metabolic and homeostatic functions. GCs act on the glucocorticoid receptor (GR), a member of the nuclear receptor family. This study identified and characterized the GR gene from the big-belly seahorse Hippocampus abdominalis designating it HaGR. The open reading frame of the HaGR cDNA was 2,346 bp in length, encoding a 782-amino-acid polypeptide with a theoretical isoelectric point of 6.26 and predicted molecular mass of 86.8 kDa. Nuclear receptors share a common structural organization, comprising an N-terminal transactivation domain, DNA-binding domain, and C-terminal ligand-binding domain. The tissue-specific mRNA expression profile of HaGR was analyzed in healthy seahorses using a qPCR technique. HaGR mRNA was expressed ubiquitously in all of the tissues examined, with the highest expression levels in kidney, intestine, stomach, and gill tissues. The mRNA expression in response to immune challenge with lipopolysaccharide (LPS), polyinosinic:polycytidylic acid (poly I:C), Edwardsiella tarda, and Streptococcus iniae revealed that it is inducible in response to pathogen infection. These results suggest that HaGR is involved in the immune response of the big-belly seahorse.

Directional adjacency-score function for protein fold recognition

  • Heo, Mu-Young;Cheon, Moo-Kyung;Kim, Suhk-Mann;Chung, Kwang-Hoon;Chang, Ik-Soo
    • Interdisciplinary Bio Central
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    • v.1 no.2
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    • pp.8.1-8.6
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    • 2009
  • Introduction: It is a challenge to design a protein score function which stabilizes the native structures of many proteins simultaneously. The coarse-grained description of proteins to construct the pairwise-contact score function usually ignores the backbone directionality of protein structures. We propose a new two-body score function which stabilizes all native states of 1,006 proteins simultaneously. This two-body score function differs from the usual pairwise-contact functions in that it considers two adjacent amino acids at two ends of each peptide bond with the backbone directionality from the N-terminal to the C-terminal. The score is a corresponding propensity for a directional alignment of two adjacent amino acids with their local environments. Results and Discussion: We show that the construction of a directional adjacency-score function was achieved using 1,006 training proteins with the sequence homology less than 30%, which include all representatives of different protein classes. After parameterizing the local environments of amino acids into 9 categories depending on three secondary structures and three kinds of hydrophobicity of amino acids, the 32,400 adjacency-scores of amino acids could be determined by the perceptron learning and the protein threading. These could stabilize simultaneously all native folds of 1,006 training proteins. When these parameters are tested on the new distinct 382 proteins with the sequence homology less than 90%, 371 (97.1%) proteins could recognize their native folds. We also showed using these parameters that the retro sequence of the SH3 domain, the B domain of Staphylococcal protein A, and the B1 domain of Streptococcal protein G could not be stabilized to fold, which agrees with the experimental evidence.

Structure and Expression of OsUBP6, an Ubiquitin-Specific Protease 6 Homolog in Rice (Oryza sativa L.)

  • Moon, Yea Kyung;Hong, Jong-Pil;Cho, Young-Chan;Yang, Sae-Jun;An, Gynheung;Kim, Woo Taek
    • Molecules and Cells
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    • v.28 no.5
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    • pp.463-472
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    • 2009
  • Although the possible cellular roles of several ubiquitin-specific proteases (UBPs) were identified in Arabidopsis, almost nothing is known about UBP homologs in rice, a monocot model plant. In this report, we searched the rice genome database (http://signal.salk.edu/cgi-bin/RiceGE) and identified 21 putative UBP family members (OsUBPs) in the rice genome. These OsUBP genes each contain a ubiquitin carboxyl-terminal hydrolase (UCH) domain with highly conserved Cys and His boxes and were subdivided into 9 groups based on their sequence identities and domain structures. RT-PCR analysis indicated that rice OsUBP genes are expressed at varying degrees in different rice tissues. We isolated a full-length cDNA clone for OsUBP6, which possesses not only a UCH domain, but also an N-terminal ubiquitin motif. Bacterially expressed OsUBP6 was capable of dismantling K48-linked tetra-ubiquitin chains in vitro. Quantitative real-time RT-PCR indicated that OsUBP6 is constitutively expressed in different tissues of rice plants. An in vivo targeting experiment showed that OsUBP6 is predominantly localized to the nucleus in onion epidermal cells. We also examined how knock-out of OsUBP6 affects developmental growth of rice plants. Although homozygous T3 osubp6 T-DNA insertion mutant seedlings displayed slower growth relative to wild type seedlings, mature mutant plants appeared to be normal. These results raise the possibility that loss of OsUBP6 is functionally compensated for by an as-yet unknown OsUBP homolog during later stages of development in rice plants.

Development of a novel endolysin, PanLys.1, for the specific inhibition of Peptostreptococcus anaerobius

  • Joonbeom Moon;Hanbeen Kim;Dongseok Lee;Jakyeom Seo
    • Animal Bioscience
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    • v.36 no.8
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    • pp.1285-1292
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    • 2023
  • Objective: The objective of this study was to develop a novel endolysin (PanLys.1) for the specific killing of the ruminal hyper-ammonia-producing bacterium Peptostreptococcus anaerobius (P. anaerobius). Methods: Whole genome sequences of P. anaerobius strains and related bacteriophages were collected from the National Center for Biotechnology Information database, and the candidate gene for PanLys.1 was isolated based on amino acid sequences and conserved domain database (CDD) analysis. The gene was overexpressed using a pET system in Escherichia coli BL21 (DE3). The lytic activity of PanLys.1 was evaluated under various conditions (dosage, pH, temperature, NaCl, and metal ions) to determine the optimal lytic activity conditions. Finally, the killing activity of PanLys.1 against P. anaerobius was confirmed using an in vitro rumen fermentation system. Results: CDD analysis showed that PanLys.1 has a modular design with a catalytic domain, amidase-2, at the N-terminal, and a cell wall binding domain, from the CW-7 superfamily, at the C-terminal. The lytic activity of PanLys.1 against P. anaerobius was the highest at pH 8.0 (p<0.05) and was maintained at 37℃ to 45℃, and 0 to 250 mM NaCl. The activity of PanLys.1 significantly decreased (p<0.05) after Mn2+ or Zn2+ treatment. The relative abundance of P. anaerobius did not decrease after administration PanLys.1 under in vitro rumen conditions. Conclusion: The application of PanLys.1 to modulate P. anaerobius in the rumen might not be feasible because its lytic activity was not observed in in vitro rumen system.

The PcG protein hPc2 interacts with the N-terminus of histone demethylase JARID1B and acts as a transcriptional co-repressor

  • Zhou, Wu;Chen, Haixiang;Zhang, Lihuang
    • BMB Reports
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    • v.42 no.3
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    • pp.154-159
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    • 2009
  • JARID1B (jumonji AT rich interactive domain 1B) is a large nuclear protein that is highly expressed in breast cancers and is proposed to function as a repressor of gene expression. In this paper, a phage display screen using the N-terminus of JARID1B as bait identified one of the JARID1B interacting proteins, namely PcG protein (Polycomb group) hPc2. We demonstrated that the C-terminal region, including the COOH box, was required for the interaction with the N-terminus of JARID1B. In a reporter assay system, co-expression of JARID1B with hPc2 significantly enhanced the transcriptional repression. These results support a role for hPc2 acting as a transcriptional co-repressor.

Cloning and Characterization of the Paraquat Resistance-Related Genes from Ochrobactrum anthropi JW-2 (Ochrobactrum anthropi JW-2 유래의 Paraquat 내성유전자 PqrA의 주변 유전자군 분석)

  • Bae Eun-Kyung;Lee Hyo-Shin;Won Sung-Hye;Lee Byung-Hyun
    • Microbiology and Biotechnology Letters
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    • v.34 no.1
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    • pp.15-22
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    • 2006
  • A 4,971 bp chromosomal DNA fragment containing the pqrA, paraquat resistance gene, was cloned from Ochrobactrum anthropi JW-2, and the complete nucleotide sequence was determined. Nucleotide and deduced amino acid sequences of the fragment revealed the presence of 4 complete ORFs (orf2, pqrA, orf3, orf4) and two incomplete ORFs(orf1, orf5). Orf1, pqrA, orf4 and orf5 exists at the direct strand but orf2 and orf3 exists at the reverse complementary strand. Orf1 which of incomplete sequences without start codon shares homology with ATP binding region of the response regulator receiver. Orf2 shares high homology with members of the tetR family of transcriptional repressor which have a helix-turn-helix (H-T-H) motif. Therefore, the orf2 is predicted as a transcriptional repressor of pqrA and is designated as pqrR2. Orf3 shares high homology with the members of the lysR family acting as a transcriptional activator which have both of a H-T-H motif at the N-terminal region and substrate binding domain at the C-terminal region. Therefore, the orf3 is predicted as a transcriptional activator of pqrA and is designated as pqrR1. Orf4 shows homology with the periplasmic substrate-binding protein of amino acid ABC transporter. Orf5 which of incomplete sequences without stop codon revealed the homology with the permeases protein of amino acid ABC transporter.