Disentangling the perturbational effects of amino acid substitutions in the DNA-binding domain of p53

1999 ◽  
Vol 104 (1) ◽  
pp. 15-22 ◽  
Author(s):  
A. I. Wacey ◽  
D. N. Cooper ◽  
D. Liney ◽  
E. Hovig ◽  
M. Krawczak
Keyword(s):  
Amino Acid ◽  
Dna Binding ◽  
Binding Domain ◽  
Amino Acid Substitutions ◽  
Dna Binding Domain

scholarly journals The C6 zinc finger and adjacent amino acids determine DNA-binding specificity and affinity in the yeast activator proteins LAC9 and PPR1.

1990 ◽  
Vol 10 (10) ◽  
pp. 5128-5137 ◽  
Author(s):  
M M Witte ◽  
R C Dickson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Dna Binding ◽  
Zinc Finger ◽  
Binding Specificity ◽  
Binding Domain ◽  
Dna Binding Domain ◽  
Transcription Activator ◽  
Activator Proteins ◽  
Dna Binding Specificity

LAC9 is a DNA-binding protein that regulates transcription of the lactose-galactose regulon in Kluyveromyces lactis. The DNA-binding domain is composed of a zinc finger and nearby amino acids (M. M. Witte and R. C. Dickson, Mol. Cell. Biol. 8:3726-3733, 1988). The single zinc finger appears to be structurally related to the zinc finger of many other fungal transcription activator proteins that contain positively charged residues and six conserved cysteines with the general form Cys-Xaa2-Cys-Xaa6-Cys-Xaa6-9-Cys-Xaa2-Cys-Xaa 6-Cys, where Xaan indicates a stretch of the indicated number of any amino acids (R. M. Evans and S. M. Hollenberg, Cell 52:1-3, 1988). The function(s) of the zinc finger and other amino acids in DNA-binding remains unclear. To determine which portion of the LAC9 DNA-binding domain mediates sequence recognition, we replaced the C6 zinc finger, amino acids adjacent to the carboxyl side of the zinc finger, or both with the analogous region from the Saccharomyces cerevisiae PPR1 or LEU3 protein. A chimeric LAC9 protein, LAC9(PPR1 34-61), carrying only the PPR1 zinc finger, retained the DNA-binding specificity of LAC9. However, LAC9(PPR1 34-75), carrying the PPR1 zinc finger and 14 amino acids on the carboxyl side of the zinc finger, gained the DNA-binding specificity of PPR1, indicating that these 14 amino acids are necessary for specific DNA binding. Our data show that C6 fingers can substitute for each other and allow DNA binding, but binding affinity is reduced. Thus, in a qualitative sense C6 fingers perform a similar function(s). However, the high-affinity binding required by natural C6 finger proteins demands a unique C6 finger with a specific amino acid sequence. This requirement may reflect conformational constraints, including interactions between the C6 finger and the carboxyl-adjacent amino acids; alternatively or in addition, it may indicate that unique, nonconserved amino acid residues in zinc fingers make sequence-specifying or stabilizing contacts with DNA.

Conserved DNA binding and self-association domains of the Drosophila zeste protein

1992 ◽  
Vol 12 (2) ◽  
pp. 598-608
Author(s):  
J D Chen ◽  
C S Chan ◽  
V Pirrotta
Keyword(s):  
Amino Acid ◽  
Dna Binding ◽  
Amino Acid Sequence ◽  
Coiled Coil ◽  
Helical Structure ◽  
Binding Activity ◽  
Binding Domain ◽  
Drosophila Virilis ◽  
Predicted Amino Acid Sequence ◽  
Dna Binding Domain

The zeste gene product is involved in two types of genetic effects dependent on chromosome pairing: transvection and the zeste-white interaction. Comparison of the predicted amino acid sequence with that of the Drosophila virilis gene shows that several blocks of amino acid sequence have been very highly conserved. One of these regions corresponds to the DNA binding domain. Site-directed mutations in this region indicate that a sequence resembling that of the homeodomain DNA recognition helix is essential for DNA binding activity. The integrity of an amphipathic helical region is also essential for binding activity and is likely to be responsible for dimerization of the DNA binding domain. Another very strongly conserved domain of zeste is the C-terminal region, predicted to form a long helical structure with two sets of heptad repeats that constitute two long hydrophobic ridges at opposite ends and on opposite faces of the helix. We show that this domain is responsible for the extensive aggregation properties of zeste that are required for its role in transvection phenomena. A model is proposed according to which the hydrophobic ridges induce the formation of open-ended coiled-coil structures holding together many hundreds of zeste molecules and possibly anchoring these complexes to other nuclear structures.

scholarly journals A novel DNA-binding motif in the nuclear matrix attachment DNA-binding protein SATB1

1994 ◽  
Vol 14 (3) ◽  
pp. 1852-1860
Author(s):  
K Nakagomi ◽  
Y Kohwi ◽  
L A Dickinson ◽  
T Kohwi-Shigematsu
Keyword(s):  
Amino Acid ◽  
Dna Binding ◽  
Direct Contact ◽  
Binding Protein ◽  
Binding Activity ◽  
Binding Domain ◽  
Binding Motif ◽  
Dna Binding Domain ◽  
Sequence Context ◽  
Dna Binding Activity

The nuclear matrix attachment DNA (MAR) binding protein SATB1 is a sequence context-specific binding protein that binds in the minor groove, making virtually no contact with the DNA bases. The SATB1 binding sites consist of a special AT-rich sequence context in which one strand is well-mixed A's, T's, and C's, excluding G's (ATC sequences), which is typically found in clusters within different MARs. To determine the extent of conservation of the SATB1 gene among different species, we cloned a mouse homolog of the human STAB1 cDNA from a cDNA expression library of the mouse thymus, the tissue in which this protein is predominantly expressed. This mouse cDNA encodes a 764-amino-acid protein with a 98% homology in amino acid sequence to the human SATB1 originally cloned from testis. To characterize the DNA binding domain of this novel class of protein, we used the mouse SATB1 cDNA and delineated a 150-amino-acid polypeptide as the binding domain. This region confers full DNA binding activity, recognizes the specific sequence context, and makes direct contact with DNA at the same nucleotides as the whole protein. This DNA binding domain contains a novel DNA binding motif: when no more than 21 amino acids at either the N- or C-terminal end of the binding domain are deleted, the majority of the DNA binding activity is lost. The concomitant presence of both terminal sequences is mandatory for binding. These two terminal regions consist of hydrophilic amino acids and share homologous sequences that are different from those of any known DNA binding motifs. We propose that the DNA binding region of SATB1 extends its two terminal regions toward DNA to make direct contact with DNA.

scholarly journals Conserved DNA binding and self-association domains of the Drosophila zeste protein.

1992 ◽  
Vol 12 (2) ◽  
pp. 598-608 ◽  
Author(s):  
J D Chen ◽  
C S Chan ◽  
V Pirrotta
Keyword(s):  
Amino Acid ◽  
Dna Binding ◽  
Amino Acid Sequence ◽  
Coiled Coil ◽  
Helical Structure ◽  
Binding Activity ◽  
Binding Domain ◽  
Drosophila Virilis ◽  
Predicted Amino Acid Sequence ◽  
Dna Binding Domain

The zeste gene product is involved in two types of genetic effects dependent on chromosome pairing: transvection and the zeste-white interaction. Comparison of the predicted amino acid sequence with that of the Drosophila virilis gene shows that several blocks of amino acid sequence have been very highly conserved. One of these regions corresponds to the DNA binding domain. Site-directed mutations in this region indicate that a sequence resembling that of the homeodomain DNA recognition helix is essential for DNA binding activity. The integrity of an amphipathic helical region is also essential for binding activity and is likely to be responsible for dimerization of the DNA binding domain. Another very strongly conserved domain of zeste is the C-terminal region, predicted to form a long helical structure with two sets of heptad repeats that constitute two long hydrophobic ridges at opposite ends and on opposite faces of the helix. We show that this domain is responsible for the extensive aggregation properties of zeste that are required for its role in transvection phenomena. A model is proposed according to which the hydrophobic ridges induce the formation of open-ended coiled-coil structures holding together many hundreds of zeste molecules and possibly anchoring these complexes to other nuclear structures.

scholarly journals A single amino acid change in CUP2 alters its mode of DNA binding.

1990 ◽  
Vol 10 (9) ◽  
pp. 4778-4787 ◽  
Author(s):  
C Buchman ◽  
P Skroch ◽  
W Dixon ◽  
T D Tullius ◽  
M Karin
Keyword(s):  
Amino Acid ◽  
Dna Binding ◽  
Binding Activity ◽  
Binding Domain ◽  
Single Amino Acid ◽  
Dna Binding Domain ◽  
Sequence Motifs ◽  
Wild Type ◽  
Mobility Shift ◽  
Single Amino Acid Change

CUP2 is a copper-dependent transcriptional activator of the yeast CUP1 metallothionein gene. In the presence of Cu+ and Ag+) ions its DNA-binding domain is thought to fold as a cysteine-coordinated Cu cluster which recognizes the palindromic CUP1 upstream activation sequence (UASc). Using mobility shift, methylation interference, and DNase I and hydroxyl radical footprinting assays, we examined the interaction of wild-type and variant CUP2 proteins produced in Escherichia coli with the UASc. Our results suggest that CUP2 has a complex Cu-coordinated DNA-binding domain containing different parts that function as DNA-binding elements recognizing distinct sequence motifs embedded within the UASc. A single-amino-acid substitution of cysteine 11 with a tyrosine results in decreased Cu binding, apparent inactivation of one of the DNA-binding elements and a dramatic change in the recognition properties of CUP2. This variant protein interacts with only one part of the wild-type site and prefers to bind to a different half-site from the wild-type protein. Although the variant has about 10% of wild-type DNA-binding activity, it appears to be completely incapable of activating transcription.

scholarly journals A specific and unusual nuclear localization signal in the DNA binding domain of the Rev-erb orphan receptors

2003 ◽  
Vol 30 (2) ◽  
pp. 197-211 ◽  
Author(s):  
S Chopin-Delannoy ◽  
S Thenot ◽  
F Delaunay ◽  
E Buisine ◽  
A Begue ◽  
...  
Keyword(s):  
Amino Acid ◽  
Dna Binding ◽  
Fusion Protein ◽  
Nuclear Receptors ◽  
Nuclear Localization ◽  
Binding Domain ◽  
Dna Binding Domain ◽  
Protein Fusion ◽  
Orphan Receptors ◽  
Amino Terminal

The orphan receptors Rev-erbalpha and Rev-erbbeta are members of the nuclear receptors superfamily and act as transcriptional repressors. Rev-erbalpha is expressed with a robust circadian rhythm and is involved in liver metabolism through repression of the ApoA1 gene, but no role has been yet defined for Rev-erbbeta. To gain better understanding of their function and mode of action, we characterized the proteins encoded by these two genes. Both Rev-erbalpha and Rev-erbbeta proteins were nuclear when transiently transfected in COS-1 cells. The major nuclear location signal (NLS) of Rev-erbalpha is in the amino-terminal region of the protein. Fusion of green fluorescent protein (GFP) to the amino terminus of Rev-erbalpha deletion mutants showed that the NLS is located within a 53 amino acid segment of the DNA binding domain (DBD). The homologous region of Rev-erbbeta fused to GFP also targeted the fusion protein to the nucleus, suggesting that the location of this NLS is conserved among all the Rev-erb group members. Interestingly, members of the phylogenetically closest nuclear orphan receptor group (ROR), which exhibit 58% amino acid identity with Rev-erb in the DBD, do not have their NLS located within the DBD. GFP/DBD. RORalpha or GFP/DBD.RORbeta remained cytoplasmic, in contrast to GFP/DBD. Rev-erb fusion proteins. Alignment of human Rev-erb and ROR DBD amino acid sequences predicted that the two basic residues, K167 and R168, located just upstream from the second zinc finger, could play a critical part in the nuclear localization of Rev-erb proteins. Substitution of these two residues with those found in ROR, in the GFP/DBD. Rev-erb context, resulted in cytoplasmic proteins. In contrast, the reverse mutation of the GFP/DBD. RORalpha towards the Rev-erbalpha residues targeted the fusion protein to the nucleus. Our data demonstrate that Rev-erb proteins contain a functional NLS in the DBD. Its location is unusual within the nuclear receptor superfamily and suggests that Rev-erb orphan receptors control their intracellular localization via a mechanism different from that of other nuclear receptors.

scholarly journals A novel DNA-binding motif in the nuclear matrix attachment DNA-binding protein SATB1.

1994 ◽  
Vol 14 (3) ◽  
pp. 1852-1860 ◽  
Author(s):  
K Nakagomi ◽  
Y Kohwi ◽  
L A Dickinson ◽  
T Kohwi-Shigematsu
Keyword(s):  
Amino Acid ◽  
Dna Binding ◽  
Direct Contact ◽  
Binding Protein ◽  
Binding Activity ◽  
Binding Domain ◽  
Binding Motif ◽  
Dna Binding Domain ◽  
Sequence Context ◽  
Dna Binding Activity

The nuclear matrix attachment DNA (MAR) binding protein SATB1 is a sequence context-specific binding protein that binds in the minor groove, making virtually no contact with the DNA bases. The SATB1 binding sites consist of a special AT-rich sequence context in which one strand is well-mixed A's, T's, and C's, excluding G's (ATC sequences), which is typically found in clusters within different MARs. To determine the extent of conservation of the SATB1 gene among different species, we cloned a mouse homolog of the human STAB1 cDNA from a cDNA expression library of the mouse thymus, the tissue in which this protein is predominantly expressed. This mouse cDNA encodes a 764-amino-acid protein with a 98% homology in amino acid sequence to the human SATB1 originally cloned from testis. To characterize the DNA binding domain of this novel class of protein, we used the mouse SATB1 cDNA and delineated a 150-amino-acid polypeptide as the binding domain. This region confers full DNA binding activity, recognizes the specific sequence context, and makes direct contact with DNA at the same nucleotides as the whole protein. This DNA binding domain contains a novel DNA binding motif: when no more than 21 amino acids at either the N- or C-terminal end of the binding domain are deleted, the majority of the DNA binding activity is lost. The concomitant presence of both terminal sequences is mandatory for binding. These two terminal regions consist of hydrophilic amino acids and share homologous sequences that are different from those of any known DNA binding motifs. We propose that the DNA binding region of SATB1 extends its two terminal regions toward DNA to make direct contact with DNA.

scholarly journals nit-4, a pathway-specific regulatory gene of Neurospora crassa, encodes a protein with a putative binuclear zinc DNA-binding domain.

1991 ◽  
Vol 11 (11) ◽  
pp. 5735-5745 ◽  
Author(s):  
G F Yuan ◽  
Y H Fu ◽  
G A Marzluf
Keyword(s):  
Amino Acid ◽  
Dna Binding ◽  
Neurospora Crassa ◽  
Transcriptional Activation ◽  
Regulatory Gene ◽  
Binding Domain ◽  
Site Directed Mutagenesis ◽  
Dna Binding Domain ◽  
Amino Terminal ◽  
Rich Domain

nit-4, a pathway-specific regulatory gene in the nitrogen circuit of Neurospora crassa, is required for the expression of nit-3 and nit-6, the structural genes which encode nitrate and nitrite reductase, respectively. The complete nucleotide sequence of the nit-4 gene has been determined. The predicted NIT4 protein contains 1,090 amino acids and appears to possess a single Zn(II)2Cys6 binuclear-type zinc finger, which may mediate DNA binding. Site-directed mutagenesis studies demonstrated that cysteine and other conserved amino acid residues in this possible DNA-binding domain are necessary for nit-4 function. A stretch of 27 glutamines, encoded by a CAGCAA repeating sequence, occurs in the C terminus of the NIT4 protein, and a second glutamine-rich domain occurs further upstream. A NIT4 protein deleted for the polyglutamine region was still functional in vivo. However, nit-4 function was abolished when both the polyglutamine region and the glutamine-rich domain were deleted, suggesting that the glutamine-rich domain might function in transcriptional activation. The homologous regulatory gene from Aspergillus nidulans, nirA, encodes a protein whose amino-terminal half has approximately 60% amino acid identity with NIT4 but whose carboxy terminus is completely different. A hybrid nit-4-nirA gene was constructed and found to function in N. crassa.

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