-incl. histones, SMC's, regulatory proteins and enzymes
first evidence of DNA packaging
experiment:
treat chromatin w/ nuclease (DNAse)
separate products by electrophorase
visualize DNA
1st level:
beads on string-nucleosomes
histone core + ~150bp DNA
Histone core
-H2A, H2B, H3, H4
histones highly conserved
high % of (+) amino acids (AA)
(25% of all AA are Lys + Arg
Do you expect DNA/histone binding to be sequence specific?
C) no
2nd level
internucleosome contacts by histone tails
histone tails
flexible
highly modified-Acetyl, Phosphate, Me, Ub
important for interactions between nucleosomes
Which of the following is not true regarding tightly compacted DNA
E.
DNA Compaction: 30nm filament: dependent on....
histone H1, histone tails
DNA Compaction: Chromosome
dependent on....
chromosome scaffold (protein)
What do chromosomes contain?
origin of replication-ARS(yeast); ORI (E. coli)
centromere
telomere (linear chromosomes)
transformation
the genetic alteration of a cell resulting from the direct uptake and incorporation of exogenous genetic material (exogenous DNA) to the cells from cells’ surroundings
transformation occurs with _____ effeciency
non-100%
colony
a visible cluster of cells growing on the surface of a solid medium, which arises from a single cell. Because the colony is clonal, with all organisms in it descending from a single ancestor cell, they are genetically identical.
the more cells in a colony, the larger the colony
no colonies
yes, colonies are present
A plasmid lacking a yeast origin of replication (ARS) will still be able to be transformed into yeast.
a)TRUE
b)FALSE