Abstract：
:By expressing a mutant trpR gene in an Escherichia coli strain that is trpR and has beta-galactosidase activity fused to the trp promoter/operator, thus putting the beta-galactosidase activity under the control of the Trp repressor, we can determine quantitatively the relative repression activity of such mutant(s). We used this technique to analyse the biological consequences of substituting certain amino acid residues in only one of the two corepressor binding pockets. By combining two compatible plasmids in this strain, one expressing the mutant T44M and the other expressing only one substitution at a time at position 85, we analysed the repression activity of the resulting interactions in vivo. This approach allowed us to engineer active dimer repressors made of two inactive or partially active monomers. Amino acid substitutions at position 85 with a positive or with an indole ring (W) appeared to complement T44M, which amino acids with a negative charge did not. Only L substitution at position 85 appeared to restore activity among the hydrophobic amino acids tested. Similar to the wild-type repressor activity, the successful mutant-mutant interactions were L-tryptophan dependent. In vivo regulation by three known L-tryptophan analogues demonstrated the same trend of regulation among the wild-type repressors and the active mutant-mutant combinations.
journal_name
J Mol Bioljournal_title
Journal of molecular biologyauthors
Storbakk N,Fenton C,Riise HM,Nilsen IW,El-Gewely MRdoi
10.1006/jmbi.1996.0135subject
Has Abstractpub_date
1996-03-15 00:00:00pages
889-96issue
5eissn
0022-2836issn
1089-8638pii
S0022283696901357journal_volume
256pub_type
杂志文章abstract：:The high resolution structures of bovine pancreatic trypsin inhibitor refined in two distinct crystal forms have been compared. One of the structures was a result of new least-squares X-ray refinement of data from crystal form I, while the other was the joint X-ray/neutron structure of crystal form II. After superposi...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/0022-2836(87)90633-4
更新日期：1987-01-05 00:00:00
abstract：:The equilibrium and kinetic folding properties of a small oncogene product, P13(MTCP1), of novel topology have been investigated using perturbation by guanidine hydrochloride and observation by fluorescence, circular dichroism and two-dimensional heteronuclear NMR spectroscopy. The structure of P13(MTCP1) is comprised...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1006/jmbi.2001.4928
更新日期：2001-09-07 00:00:00
abstract：:The process of deducing the catalytic mechanism of an enzyme from its structure is highly complex and requires extensive experimental work to validate a proposed mechanism. As one step towards improving the reliability of this process, we have gathered statistics describing the typical geometry of catalytic residues w...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/j.jmb.2007.03.055
更新日期：2007-06-15 00:00:00
abstract：:Ricin A-chain is an N-glycosidase that hydrolyzes the adenine ring from a specific adenosine of rRNA. Formycin monophosphate (FMP) and adenyl(3'-->5')guanosine (ApG) were bound to ricin A-chain and their structures elucidated by X-ray crystallography. The formycin ring stacks between tyrosines 80 and 123 and at least ...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/0022-2836(92)90526-p
更新日期：1992-10-20 00:00:00
abstract：:The binding of tryptophan repressor (TrpR) to its operators was examined quantitatively using in vitro and in vivo methods. DNA sequence requirements for 1:1 and tandem 2:1 (TrpR:DNA) binding in various sequence contexts were studied. The results indicate that the optimal half-site sequence for recognition by one heli...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1006/jmbi.1996.0232
更新日期：1996-04-26 00:00:00
abstract：:R2 elements are non-long terminal repeat (non-LTR) retrotransposons with a single open reading-frame encoding reverse transcriptase, DNA endonuclease and nucleic acid-binding domains. The elements are specialized for insertion into the 28 S rRNA genes of many animal phyla. The R2-encoded activities initiate retrotrans...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/j.jmb.2007.09.047
更新日期：2007-11-23 00:00:00
abstract：:The bacterial enzyme maltodextrin phosphorylase (MalP) catalyses the phosphorolysis of an alpha-1,4-glycosidic bond in maltodextrins, removing the non-reducing glucosyl residues of linear oligosaccharides as glucose-1-phosphate (Glc1P). In contrast to the well-studied muscle glycogen phosphorylase (GP), MalP exhibits ...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/s0022-2836(02)00771-4
更新日期：2002-09-13 00:00:00
abstract：:The adaptor protein Tks5/FISH (tyrosine kinase substrate 5/five SH3 domains, hereafter termed Tks5) is a crucial component of a protein network that controls the invasiveness of cancer cells and progression of Alzheimer's disease. Tks5 consists of an amino-terminal PX domain that is followed by five SH3 domains (SH3A-...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/j.jmb.2009.05.025
更新日期：2009-07-31 00:00:00
abstract：:Crystallization of membrane proteins is a major stumbling block en route to elucidating their structure and understanding their function. The novel concept of membrane protein crystallization from lipidic cubic phases, "in cubo", has yielded well-ordered crystals and high-resolution structures of several membrane prot...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/j.jmb.2004.09.022
更新日期：2004-11-05 00:00:00
abstract：:Sequence-specific interactions between proteins and DNA are essential for a variety of biological functions. The (cytosine-C5)-methyltransferase from HhaI (M.HhaI) specifically modifies the second base in GCGC sequences, employing a base flipping mechanism to access the target base being chemically modified. The mecha...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/j.jmb.2004.10.042
更新日期：2005-01-14 00:00:00
abstract：:The tyrosine residues adjacent to the C termini of the hemoglobin (Hb) subunits, alphaY140 and betaY145, are expected to play important structural roles, because the C termini are the loci of T-state quaternary salt-bridges, and because the tyrosine side-chains bridge the H and F helices via H bonds to the alphaV93 an...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/j.jmb.2005.11.006
更新日期：2006-02-17 00:00:00
abstract：:Mutants of an archaeon Halobacterium halobium, resistant to the universal inhibitor of translation, pactamycin, were isolated. Pactamycin resistance correlated with the presence of mutations in the 16 S rRNA gene of H. halobium single rRNA operon. Three types of mutations were found in pactamycin resistant cells, A694...
journal_title：Journal of molecular biology
pub_type： 杂志文章,评审
doi：10.1006/jmbi.1997.1387
更新日期：1997-11-21 00:00:00
abstract：:We quantify the degree to which folding occurs along a complex landscape with structurally distinct pathways using psi-analysis in combination with a protein engineering method that identifies native, non-covalent polypeptide interactions and their relative populations at the rate-limiting step. By probing the proximi...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/j.jmb.2004.01.018
更新日期：2004-03-19 00:00:00
abstract：:The second generation Hoechst-Bayer non-nucleoside inhibitor, HBY 097 (S-4-isopropoxycarbonyl-6-methoxy-3-(methylthiomethyl)-3, 4-dihydroqui noxalin-2(1H)-thione), is an extremely potent inhibitor of HIV-1 reverse transcriptase (RT) and of HIV-1 infection in cell culture. HBY 097 selects for unusual drug-resistance mu...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1006/jmbi.1998.2171
更新日期：1998-11-27 00:00:00
abstract：:The major allergens of honeybee venom, hyaluronidase (Hyal) and phospholipase A2, can induce life-threatening IgE-mediated allergic reactions in humans. Although conventional immunotherapy is effective, up to 40% of patients develop allergic side effects including anaphylaxis and thus, there is a need for an improved ...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/j.jmb.2007.02.036
更新日期：2007-05-04 00:00:00
abstract：:The structure of the actin-myosin complex during ATP hydrolysis was studied by covalently crosslinking myosin subfragment 1 (S1) to F-actin in the presence of nucleotides (especially ATP) using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide. The fluorescence energy transfer was measured between N-(iodoacetyl)-N'-(1-sul...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/0022-2836(86)90426-2
更新日期：1986-09-05 00:00:00
abstract：:Ebolaviruses are causative agents of lethal hemorrhagic fever in humans and nonhuman primates. Among the filoviruses characterized thus far, Reston Ebola virus (REBOV) is the only Ebola virus that is nonpathogenic to humans despite the fact that REBOV can cause lethal disease in nonhuman primates. Previous studies als...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/j.jmb.2010.04.022
更新日期：2010-06-11 00:00:00
abstract：:Insertion and deletion mutagenesis within the gene topA of Escherichia coli encoding DNA topoisomerase I was carried out to test the existence of subdomains in the enzyme and the relationship between the slow-growth topA- phenotype and the known DNA relaxation activity of the enzyme. All mutants that show no detectabl...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/0022-2836(86)90130-0
更新日期：1986-10-05 00:00:00
abstract：:Allosteric regulatory processes are implicated at all levels of biological function. Recent advances in our understanding of the diverse and functionally significant class of intrinsically disordered proteins have identified a multitude of ways in which disordered proteins function within the confines of the allosteri...
journal_title：Journal of molecular biology
pub_type： 杂志文章,评审
doi：10.1016/j.jmb.2018.04.003
更新日期：2018-08-03 00:00:00
abstract：:The cyclin-dependent kinase inhibitors (CKIs) bind to and directly regulate the catalytic activity of cyclin-dependent kinase (Cdk)/cyclin complexes involved in cell cycle control and do not regulate other, closely related Cdks. We showed previously that the CKI, p27, binds to Cdk2/cyclin A though a sequential mechani...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/j.jmb.2005.04.019
更新日期：2005-06-17 00:00:00
abstract：:Deleted in Split hand/Split foot 1 (DSS1) was previously identified as a novel 12-O-tetradecanoylphorbol-13-acetate (TPA)-inducible gene with possible involvement in early event of mouse skin carcinogenesis. The mechanisms by which human DSS1 (HsDSS1) exerts its biological effects via regulation of the ubiquitin-prote...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/j.jmb.2008.08.044
更新日期：2008-11-14 00:00:00
abstract：:As a model to examine the local distribution of sequence variation within large arrays of tandemly repeated DNA in complex genomes, the long-range organization of alpha-satellite DNA from human chromosome 17 was investigated. Three individual chromosomes, representing different alpha-satellite haplotypes, were segrega...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/s0022-2836(05)80056-7
更新日期：1990-11-05 00:00:00
abstract：:A duck delta II crystallin mutant, where histidine 178 has been replaced by an aspartic acid residue, has been purified from a bacterial expression system and subsequently crystallized. The crystals grow as flat plates, with unit cell dimensions a = 94.1 A, b = 99.9 A, c = 108.7 A and beta = 102 degrees. The crystals ...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1006/jmbi.1994.1694
更新日期：1994-11-11 00:00:00
abstract：:Iron uptake by transferrin from triacetohydroxamatoFe(III) (Fe(AHA)3) in the presence of bicarbonate has been investigated between pH 7 and 8.2. The protein transits from the opened apo- to the closed holoform by several steps with the accumulation of at least three kinetic intermediates. All these steps are accompani...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1006/jmbi.1999.3238
更新日期：1999-11-12 00:00:00
abstract：:A new type of solute importer has been identified recently in various bacterial genera and called the tripartite tricarboxylate transporter (TTT). TTTs consist of two cytoplasmic membrane proteins and a periplasmic solute-binding protein. In the whooping cough agent Bordetella pertussis, a TTT system that has been cal...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/j.jmb.2005.05.071
更新日期：2005-08-26 00:00:00
abstract：:A large survey of reliably known structures supports the hypothesis that protein loops can behave like elastic strings, and has enabled a parameter describing the entropically generated tensions to be determined. Such tensions may be of major importance in the folding process; here they are discussed mainly in the con...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/S0022-2836(05)80334-1
更新日期：1990-11-20 00:00:00
abstract：:Bacteriophage λ of Escherichia coli has two alternative life cycles after infection-host survival with lysogen formation, or host lysis and phage production. In a lysogen, CI represses the two lytic promoters, pR and pL, and activates its own transcription from the auto-regulated pRM promoter. During induction from th...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/j.jmb.2017.11.005
更新日期：2018-01-05 00:00:00
abstract：:To study mechanisms of nucleosome positioning, small circular plasmids were constructed, assembled into chromatin in vivo in Saccharomyces cerevisiae, and their chromatin structures were analysed with respect to positions of nucleosomes and nuclease-sensitive regions. Plasmids used include insertions of the URA3 gene ...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/0022-2836(86)90291-3
更新日期：1986-07-20 00:00:00
abstract：:The lectin from the mushroom Psathyrella velutina recognises specifically N-acetylglucosamine and N-acetylneuraminic acid containing glycans. The crystal structure of the 401 amino acid residue lectin shows that it adopts a very regular seven-bladed beta-propeller fold with the N-terminal region tucked into the centra...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/j.jmb.2006.01.066
更新日期：2006-04-14 00:00:00
abstract：:The mitochondrial inner membrane consists of two morphologically distinct domains, the inner boundary membrane and large invaginations termed cristae. Narrow membrane structures, the crista junctions, link these two domains. Maintenance of this elaborate architecture depends on the evolutionarily conserved mitochondri...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/j.jmb.2016.02.031
更新日期：2016-04-24 00:00:00
