-

.

: 107k

, , .

:

.

. 5 3.

dNTP NTP

dsDNA A-T, G-C

A-U, T-A, G-C

: .

-

, , , .

, .

. .

. , ..

5' 3'

GCAGTACATGTC CGTCATGTACAG

3' coding 5'

strand template strand

transcription

5'

GCAGUACAUGUC

3'

RNA

. . This feature is referred to as the asymmetric transcription.

5' 3'

3' 5'

, 5 3 . 5 3 . The prokaryotic RNA polymerase is a multiple-

subunit protein of ~480kD. Eukaryotic systems have three kinds of RNA

polymerases, each of which is a multiplesubunit protein and responsible for transcription of different RNAs.

: ; 5 . 5 : 1. 2 ; 2. ; 3. ;

E.coli

5 : 2 .

holoenzyme core enzyme

E. Coli

MW36512 150618

15561370263

. NTP , ,

RNA-pol

I

II

III

- .

.

, . .

,

, .

regulatory sequences5' 3'

structural gene3' 5'

promotor RNA-pol

5' -50 3' -40 -30 -20 -10 1 10 3' 5'

-35 region TTGACA AACTGT

-10 region TATAAT ATATTA (Pribnow box)

start

Consensus sequence

Consensus Sequence

Frequency in 45 samples

38 36 29 37 37 28

40 25 30 41 29 44

:

, ( ) .

5-TTGACA-3 35 . 5-TATAAT-3 10 .

: , , . RNA-pol . RNA-pol

(TF-) .

: RNA-pol , .

: .: the RNA-pol , .

a. ; ;

()

b. . 5 3 . NTPs 3 -OH .(NMP)n + NTPRNA strand substrate

(NMP)n+1 + PPielongated RNA strand

RNA-pol of E. Coli

RNA-pol of E. Coli

c. - .

rplL DNA5TTGCAGCCTGACAAATCAGGCTGATGGCTGGTGACTTTTTAGGCACCAGCCTTTTT... 35TTGCAGCCTGACAAATCAGGCTGATGGCTGGTGACTTTTTAGTCACCAGCCTTTTT... 3

RNAUUUU...

UUUU...

a.

.

, .

cis-acting elementstructural geneGCGC CAAT TATA exon intron exon

startTATA box

(Hogness box)

enhancerGC box

CAAT box

TATA

RNA-pol . RNA-pol II 6

, TFII A - TFII H. , .

TF

b.

.

.

nucleosomeRNA-Pol

moving direction

RNA-Pol

RNA-Pol

c. AATAAA GT . .

111 !!!