Molecular Genetics 15

domains

specialized area of proteins that take care of a specific function

gene expression

genetic information is assessed

combinatorial control

a combination of different factors transcriptionally regulating the gene

gene regulation

the dial that controls gene expression, turning it up or down

motif

amino acid sequence or domain with similar structure and function in many proteins

factors that affect gene transcription

• precise positioning of nucleosomes near promoters

• histone variants being present

• covalent modifications of histones

covalent modifications

• acetylation

• methylation

• phosphorylation

DNA translocase

protein complex that recognizes nucleosomes and uses ATP to alter their configuration

ways that regulatory transcription factors can be modulated

• protein protein factors-homo/heterodimers

• binding of small effector molecules-steroid hormones

• covalent modifications-attachment of phosphate group

chromatic remodeling tactics

• changes positions of nucleosomes

• histone octamers are evicted and creates gaps

• changes composition of nucleosomes by removing standard histones and putting histone variants

histone variants and their job

• histones with accumulated mutations that change amino acid sequences in histones

• their job is the regulate the structure of chromatin, which influences gene transcription

histone

a group of proteins found in chromatin

euchromatin vs heterochromatin

eu is loosely compacted, hetero is tightly compacted

enhancer

region of DNA that contains one or more regulatory elements

up regulation

when and activator binds to an enhancer

down regulation

when a repressor binds to an enhancer

dimer

structure/molecule made of two similar or identical units

general transcription factors

required for binding of RNA polymerase to core promoter and for progression to elongation

regulatory transcription factors

regulate the speed of transcription

motif examples

• helix-turn-helix

• helix-loop-helix

• zinc finger

• leucine zipper