Corresponds to three different RNA polymerases and related proteins

Class I promoter

Class II promoter

Class III promoter

Cis-acting elements that can enhance the efficiency of eukaryotic promoters are the most important regulatory sequences of eukaryotic genes and determine the expression level of each gene in the cell.

any direction and any location

Different enhancers bind different regulatory proteins

definition

It is a large cluster of transcriptionally active enhancers that is highly enriched. degree of key transcription factors, cofactors, etc., so it is increased than ordinary The expression level of genes regulated by hadrons is much higher, which is very important for transcription factors. blocking is more sensitive

Specific DNA sequences that can inhibit gene transcription, combine with trans-acting factors to repress gene transcription, and silence genes.

Complementary copies of the same sequence are arranged in reverse order on the DNA strand

300bp or slightly shorter, accounting for 5% of the human genome

Scattered rather than clustered throughout the genome

Classification

Features

Inverted repeats are binding sites for enzymes involved in the initiation of DNA replication

Hairpin structures (which some inverted repeats can form) help stabilize RNA molecules

Synapsis between homologous chromosomes may rely on specific satellite DNA sequences with chromosomal specificity

Highly repetitive nucleotide sequences are species specific

Short repeating sequences scattered throughout the genome

The average length is 300-500bp, and the number of copies can reach hundreds of thousands.

Such as Alu, KpnI, and Hinf families, etc.

Scattered distribution of long repetitive sequences in the genome

The average length is more than 1000bp

Often have transposition activity

rRNA genes usually exist in clusters rather than scattered throughout the genome

Histone gene family

human globin gene family

The polypeptide chain folding pattern of many cell membrane surface and certain protein molecules in the body is similar to that of Ig, and it has high homology with IgV region or C region at the DNA level and amino acid sequence. The products encoded by this gene superfamily are called immunoglobulin superfamily (IGSF)

The mature mRNA generated by gene transcription is reverse transcribed to produce cDNA, which is then integrated into chromosomal DNA and may become a pseudogene.