scholarly journals Identification of evolutionarily conserved amino acid residues in homeodomain of KNOX proteins for intercellular trafficking

2014 ◽  
Vol 9 (2) ◽  
pp. e28355 ◽  
Author(s):  
Huan Chen ◽  
David Jackson ◽  
Jae-Yean Kim
Keyword(s):  
Amino Acid ◽  
Amino Acid Residues ◽  
Intercellular Trafficking ◽  
Evolutionarily Conserved ◽  
Knox Proteins

scholarly journals A Molecular Genetic Dissection of the Evolutionarily Conserved N Terminus of Yeast Rad52

Genetics ◽  
2002 ◽  
Vol 161 (2) ◽  
pp. 549-562
Author(s):  
Uffe H Mortensen ◽  
Naz Erdeniz ◽  
Qi Feng ◽  
Rodney Rothstein
Keyword(s):  
Dna Damage ◽  
Amino Acid ◽  
Dna Binding ◽  
Molecular Genetic ◽  
Mitotic Recombination ◽  
Amino Acid Residues ◽  
Γ Irradiation ◽  
Evolutionarily Conserved ◽  
N Terminus ◽  
Γ Ray

Abstract Rad52 is a DNA-binding protein that stimulates the annealing of complementary single-stranded DNA. Only the N terminus of Rad52 is evolutionarily conserved; it contains the core activity of the protein, including its DNA-binding activity. To identify amino acid residues that are important for Rad52 function(s), we systematically replaced 76 of 165 amino acid residues in the N terminus with alanine. These substitutions were examined for their effects on the repair of γ-ray-induced DNA damage and on both interchromosomal and direct repeat heteroallelic recombination. This analysis identified five regions that are required for efficient γ-ray damage repair or mitotic recombination. Two regions, I and II, also contain the classic mutations, rad52-2 and rad52-1, respectively. Interestingly, four of the five regions contain mutations that impair the ability to repair γ-ray-induced DNA damage yet still allow mitotic recombinants to be produced at rates that are similar to or higher than those obtained with wild-type strains. In addition, a new class of separation-of-function mutation that is only partially deficient in the repair of γ-ray damage, but exhibits decreased mitotic recombination similar to rad52 null strains, was identified. These results suggest that Rad52 protein acts differently on lesions that occur spontaneously during the cell cycle than on those induced by γ-irradiation.

scholarly journals Coevolution-based inference of amino acid interactions underlying protein function

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Victor H Salinas ◽  
Rama Ranganathan
Keyword(s):  
Amino Acid ◽  
Protein Function ◽  
Structural Basis ◽  
Amino Acid Residues ◽  
Physical Constraints ◽  
Cooperative Interactions ◽  
Evolutionarily Conserved ◽  
Statistical Coupling ◽  
Energetic Interactions ◽  
Statistical Coupling Analysis

Protein function arises from a poorly understood pattern of energetic interactions between amino acid residues. Sequence-based strategies for deducing this pattern have been proposed, but lack of benchmark data has limited experimental verification. Here, we extend deep-mutation technologies to enable measurement of many thousands of pairwise amino acid couplings in several homologs of a protein family – a deep coupling scan (DCS). The data show that cooperative interactions between residues are loaded in a sparse, evolutionarily conserved, spatially contiguous network of amino acids. The pattern of amino acid coupling is quantitatively captured in the coevolution of amino acid positions, especially as indicated by the statistical coupling analysis (SCA), providing experimental confirmation of the key tenets of this method. This work exposes the collective nature of physical constraints on protein function and clarifies its link with sequence analysis, enabling a general practical approach for understanding the structural basis for protein function.

scholarly journals EBNA2 Amino Acids 3 to 30 Are Required for Induction of LMP-1 and Immortalization Maintenance

2004 ◽  
Vol 78 (8) ◽  
pp. 3919-3929 ◽  
Author(s):  
Alexey V. Gordadze ◽  
Chisaroka W. Onunwor ◽  
RongSheng Peng ◽  
David Poston ◽  
Elisabeth Kremmer ◽  
...  
Keyword(s):  
Amino Acid ◽  
B Cell ◽  
Cell Transformation ◽  
Nuclear Antigen ◽  
Amino Acid Residues ◽  
Barr Virus ◽  
Amino Terminal ◽  
Cellular Genes ◽  
Evolutionarily Conserved ◽  
Epstein Barr

ABSTRACT Epstein-Barr virus (EBV) nuclear antigen 2 (EBNA2), a direct transcriptional activator of viral and cellular genes, is required for EBV-induced B-cell transformation. The functional role of conserved regions within the amino terminus of the protein preceding the poly-proline region has yet to be fully characterized. Thus, we tested whether the EBNA2 amino-terminal 30 amino acid residues, containing evolutionarily conserved region 1, are required for stimulating viral and cellular gene expression necessary for B-cell transformation in a viral transcomplementation assay. We found that these residues are required for its ability to induce LMP-1 expression in lymphoblastoid cell lines (LCLs), to stimulate LMP-1 promoter reporter plasmids in transient-cotransfection assays, and to rescue LCL growth following inactivation of endogenous wild-type EBNA2 protein. Deletion of amino acid residues 3 to 30 also impaired its ability to self-associate in coimmunoprecipitation assays. These data indicate that EBNA2 residues 3 to 30 comprise an essential domain required for induction of LMP-1 expression and, consequently, for maintenance of the immortalized phenotype of LCLs. The ability to self-associate into dimers or multimers conferred by this domain may be an important mechanism for these effects.

Substrate Recognition by Vitamin K-Dependent Carboxylase

1987 ◽  
Vol 57 (01) ◽  
pp. 017-019 ◽  
Author(s):  
Magda M W Ulrich ◽  
Berry A M Soute ◽  
L Johan M van Haarlem ◽  
Cees Vermeer
Keyword(s):  
Amino Acid ◽  
Vitamin K ◽  
Substrate Recognition ◽  
Bovine Liver ◽  
Amino Acid Residues

SummaryDecarboxylated osteocalcins were prepared and purified from bovine, chicken, human and monkey bones and assayed for their ability to serve as a substrate for vitamin K-dependent carboxylase from bovine liver. Substantial differences were observed, especially between bovine and monkey d-osteocalcin. Since these substrates differ only in their amino acid residues 3 and 4, it seems that these residues play a role in the recognition of a substrate by hepatic carboxylase.

Statistical Force-Field for Structural Modeling Using Chemical Cross-Linking/mass Spectrometry Distance Constraints

2018 ◽  
Author(s):  
Allan J. R. Ferrari ◽  
Fabio C. Gozzo ◽  
Leandro Martinez
Keyword(s):  
Mass Spectrometry ◽  
Amino Acid ◽  
Force Field ◽  
Protein Structures ◽  
Protein Structure Determination ◽  
Structural Modeling ◽  
Cross Linking ◽  
Amino Acid Residues ◽  
Distance Constraints ◽  
Chemical Cross Linking

<div><p>Chemical cross-linking/Mass Spectrometry (XLMS) is an experimental method to obtain distance constraints between amino acid residues, which can be applied to structural modeling of tertiary and quaternary biomolecular structures. These constraints provide, in principle, only upper limits to the distance between amino acid residues along the surface of the biomolecule. In practice, attempts to use of XLMS constraints for tertiary protein structure determination have not been widely successful. This indicates the need of specifically designed strategies for the representation of these constraints within modeling algorithms. Here, a force-field designed to represent XLMS-derived constraints is proposed. The potential energy functions are obtained by computing, in the database of known protein structures, the probability of satisfaction of a topological cross-linking distance as a function of the Euclidean distance between amino acid residues. The force-field can be easily incorporated into current modeling methods and software. In this work, the force-field was implemented within the Rosetta ab initio relax protocol. We show a significant improvement in the quality of the models obtained relative to current strategies for constraint representation. This force-field contributes to the long-desired goal of obtaining the tertiary structures of proteins using XLMS data. Force-field parameters and usage instructions are freely available at http://m3g.iqm.unicamp.br/topolink/xlff <br></p></div><p></p><p></p>

Sign in / Sign up

Export Citation Format

Share Document