dna binding protein(motif)
TRANSCRIPT
![Page 1: Dna binding protein(motif)](https://reader036.vdocuments.us/reader036/viewer/2022062412/589ff8631a28ab46598b5d3f/html5/thumbnails/1.jpg)
DNA-binding Proteins and Their Attachment
Sites
![Page 2: Dna binding protein(motif)](https://reader036.vdocuments.us/reader036/viewer/2022062412/589ff8631a28ab46598b5d3f/html5/thumbnails/2.jpg)
• X-ray crystallography
• nuclear magnetic resonance (NMR) spectroscopy
THE STRUCTURES OF MANY PROTEINS HAVE BEEN DETERMINED BY :
Motifs are structural characteristics domains are functional regions
![Page 3: Dna binding protein(motif)](https://reader036.vdocuments.us/reader036/viewer/2022062412/589ff8631a28ab46598b5d3f/html5/thumbnails/3.jpg)
![Page 4: Dna binding protein(motif)](https://reader036.vdocuments.us/reader036/viewer/2022062412/589ff8631a28ab46598b5d3f/html5/thumbnails/4.jpg)
Helix-turn-helix (HTH)• turn made up of four amino acids, the second of which is usually glycine• second a-helix is therefore the recognition helix • lactose repressor• The Homeodomain is an extended HTH motif (antennapodia , pax, SRY)•POU domain which is usually found in proteins that also have a homeodomain• winged helix–turn–helix ( GABP )
![Page 5: Dna binding protein(motif)](https://reader036.vdocuments.us/reader036/viewer/2022062412/589ff8631a28ab46598b5d3f/html5/thumbnails/5.jpg)
![Page 6: Dna binding protein(motif)](https://reader036.vdocuments.us/reader036/viewer/2022062412/589ff8631a28ab46598b5d3f/html5/thumbnails/6.jpg)
![Page 7: Dna binding protein(motif)](https://reader036.vdocuments.us/reader036/viewer/2022062412/589ff8631a28ab46598b5d3f/html5/thumbnails/7.jpg)
![Page 8: Dna binding protein(motif)](https://reader036.vdocuments.us/reader036/viewer/2022062412/589ff8631a28ab46598b5d3f/html5/thumbnails/8.jpg)
![Page 9: Dna binding protein(motif)](https://reader036.vdocuments.us/reader036/viewer/2022062412/589ff8631a28ab46598b5d3f/html5/thumbnails/9.jpg)
Zinc fingers• very common in eukaryotes•There are at least six different versions of the zinc finger
Cys2His2 finger-comprises a series of 12 or so amino acids, including two cysteines and two histidines- α helix is recognition-the zinc atom holds the b-sheet and a-helix in the appropriate positions relative to one another-TFIIIA , SW15- multicysteine zinc fingers (steroid receptor)
![Page 10: Dna binding protein(motif)](https://reader036.vdocuments.us/reader036/viewer/2022062412/589ff8631a28ab46598b5d3f/html5/thumbnails/10.jpg)
![Page 11: Dna binding protein(motif)](https://reader036.vdocuments.us/reader036/viewer/2022062412/589ff8631a28ab46598b5d3f/html5/thumbnails/11.jpg)
![Page 12: Dna binding protein(motif)](https://reader036.vdocuments.us/reader036/viewer/2022062412/589ff8631a28ab46598b5d3f/html5/thumbnails/12.jpg)
OTHER NUCLEIC ACID–BINDING MOTIFS basic domain : DNA recognition structure is an a-helix that contains a high number of basic amino acids (ser ,arg,thr) ribbon–helix–helix : use of two strands of a b-sheet as the recognition structure (Met J)
![Page 13: Dna binding protein(motif)](https://reader036.vdocuments.us/reader036/viewer/2022062412/589ff8631a28ab46598b5d3f/html5/thumbnails/13.jpg)
TBP domain: the recognition structure is a b-sheet (the main contacts are with the minor, not major, groove of the DNA)leucine zipper : is an a-helix that coils more tightly than normal and presents a series of leucines on one of its faces (c-Jun , c-Fos )
![Page 14: Dna binding protein(motif)](https://reader036.vdocuments.us/reader036/viewer/2022062412/589ff8631a28ab46598b5d3f/html5/thumbnails/14.jpg)
helix–loop–helix :
- E1 , E2 , Myo D , Myc
![Page 15: Dna binding protein(motif)](https://reader036.vdocuments.us/reader036/viewer/2022062412/589ff8631a28ab46598b5d3f/html5/thumbnails/15.jpg)
RNA-BINDING PROTEINS : Ribonucleoprotein (RNP) domain : comprises four β-strands and two α-helices in the order β-α-β-β-α-β
double-stranded RNA binding domain (dsRBD) : the structure α-β-β-β-α
κ-homology domain : the structure β-α-α-β-β-α
![Page 16: Dna binding protein(motif)](https://reader036.vdocuments.us/reader036/viewer/2022062412/589ff8631a28ab46598b5d3f/html5/thumbnails/16.jpg)
GEL RETARDATION IDENTIFIES DNA FRAGMENTS THAT BIND TO PROTEINS
![Page 17: Dna binding protein(motif)](https://reader036.vdocuments.us/reader036/viewer/2022062412/589ff8631a28ab46598b5d3f/html5/thumbnails/17.jpg)
MODIFICATION PROTECTION
![Page 18: Dna binding protein(motif)](https://reader036.vdocuments.us/reader036/viewer/2022062412/589ff8631a28ab46598b5d3f/html5/thumbnails/18.jpg)
MODIFICATION INTERFERENCE
![Page 19: Dna binding protein(motif)](https://reader036.vdocuments.us/reader036/viewer/2022062412/589ff8631a28ab46598b5d3f/html5/thumbnails/19.jpg)
Mutations in the GLI3 gene cause Greig cephalopolysyndactyly syndromeThe GLI3 gene provides instructions for making a protein that controls gene expression
GREIG CEPHALOPOLYSYNDACTYLY SYNDROME
![Page 20: Dna binding protein(motif)](https://reader036.vdocuments.us/reader036/viewer/2022062412/589ff8631a28ab46598b5d3f/html5/thumbnails/20.jpg)
WILMS TUMOR AND DENYS-DRASH SYNDROME•The WT1 gene provides instructions for making a protein that is necessary for the development of the kidneys and gonads .
•The mutations that cause Denys-Drash syndrome lead to the production of an abnormal WT1 protein that cannot bind to DNA
![Page 21: Dna binding protein(motif)](https://reader036.vdocuments.us/reader036/viewer/2022062412/589ff8631a28ab46598b5d3f/html5/thumbnails/21.jpg)
HOLOPROSENCEPHALY• Mutations in 11 genes have been found to cause nonsyndromic holoprosencephaly.•The ZIC2 protein regulates genes involved in both early and late stages of forebrain development
![Page 22: Dna binding protein(motif)](https://reader036.vdocuments.us/reader036/viewer/2022062412/589ff8631a28ab46598b5d3f/html5/thumbnails/22.jpg)
Mahdevar