8f1k

SigN RNA polymerase early-melted intermediate bound to full duplex DNA fragment dhsU36 (-12T)

Method: ELECTRON MICROSCOPY

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1. Protein Identity and Related Structures Protein Identity & Related Structures

DNA-directed RNA polymerase subunit alpha

Escherichia coli

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein–DNA	Heteromer	Protein 6 DNA 4	DNA (36-MER) × 2 DNA-directed RNA polymerase subunit beta × 1 （P0A8V2） ;DNA-directed RNA polymerase subunit beta' ; × 1 （P0A8T7） DNA-directed RNA polymerase subunit omega × 1 （P0A800） RNA polymerase sigma-54 factor × 1 （P24255） DNA (36-MER) × 2 MAGNESIUM ION × 1 ZINC ION × 2 water × 3	Consistent with all polymers

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	RPOA_ECOLI
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain G； PDBConstruct 1–329； UniProt 1–329 Author chain H； PDBConstruct 1–329； UniProt 1–329

DNA-directed RNA polymerase subunit beta

Escherichia coli

UniProt P0A8V2

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein–DNA	Heteromer	Protein 6 DNA 4	DNA (36-MER) × 2 DNA-directed RNA polymerase subunit alpha × 2 （P0A7Z4） ;DNA-directed RNA polymerase subunit beta' ; × 1 （P0A8T7） DNA-directed RNA polymerase subunit omega × 1 （P0A800） RNA polymerase sigma-54 factor × 1 （P24255） DNA (36-MER) × 2 MAGNESIUM ION × 1 ZINC ION × 2 water × 3	Consistent with all polymers

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	RPOB_ECOLI
Isoform	—
PDB entities	3
Chains and sequence ranges	Author chain I； PDBConstruct 1–1342； UniProt 1–1342

;DNA-directed RNA polymerase subunit beta' ;

Escherichia coli

UniProt P0A8T7

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein–DNA	Heteromer	Protein 6 DNA 4	DNA (36-MER) × 2 DNA-directed RNA polymerase subunit alpha × 2 （P0A7Z4） DNA-directed RNA polymerase subunit beta × 1 （P0A8V2） DNA-directed RNA polymerase subunit omega × 1 （P0A800） RNA polymerase sigma-54 factor × 1 （P24255） DNA (36-MER) × 2 MAGNESIUM ION × 1 ZINC ION × 2 water × 3	Consistent with all polymers

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	RPOC_ECOLI
Isoform	—
PDB entities	4
Chains and sequence ranges	Author chain J； PDBConstruct 1–1407； UniProt 1–1407

DNA-directed RNA polymerase subunit omega

Escherichia coli

UniProt P0A800

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein–DNA	Heteromer	Protein 6 DNA 4	DNA (36-MER) × 2 DNA-directed RNA polymerase subunit alpha × 2 （P0A7Z4） DNA-directed RNA polymerase subunit beta × 1 （P0A8V2） ;DNA-directed RNA polymerase subunit beta' ; × 1 （P0A8T7） RNA polymerase sigma-54 factor × 1 （P24255） DNA (36-MER) × 2 MAGNESIUM ION × 1 ZINC ION × 2 water × 3	Consistent with all polymers

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	RPOZ_ECOLI
Isoform	—
PDB entities	5
Chains and sequence ranges	Author chain K； PDBConstruct 1–91； UniProt 1–91

RNA polymerase sigma-54 factor

Escherichia coli

UniProt P24255

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein–DNA	Heteromer	Protein 6 DNA 4	DNA (36-MER) × 2 DNA-directed RNA polymerase subunit alpha × 2 （P0A7Z4） DNA-directed RNA polymerase subunit beta × 1 （P0A8V2） ;DNA-directed RNA polymerase subunit beta' ; × 1 （P0A8T7） DNA-directed RNA polymerase subunit omega × 1 （P0A800） DNA (36-MER) × 2 MAGNESIUM ION × 1 ZINC ION × 2 water × 3	Consistent with all polymers

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	RP54_ECOLI
Isoform	—
PDB entities	6
Chains and sequence ranges	Author chain M； PDBConstruct 4–480； UniProt 1–477

The page prioritizes protein identity, the current assembly, associated components, oligomeric state and cross-PDB links. Chain mapping and sequence ranges are retained as data evidence. Internal IDs, import timestamps and assembly operation expressions are maintenance fields and are not shown here.

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2. Structure Basics 2. Structure Basics

Entry ID entry_id	8f1k
Deposition date deposition_date	2022-11-05
Structure title title	SigN RNA polymerase early-melted intermediate bound to full duplex DNA fragment dhsU36 (-12T)
Keywords keywords	promoter-bound, initiation, DNA melting, transcription bubble nucleation, TRANSCRIPTION, TRANSCRIPTION-DNA complex; TRANSCRIPTION/DNA
Experimental Method method	ELECTRON MICROSCOPY

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3. Official assembly/model SAXS Official SAXS Profiles

This page reads only the latest assembly calculations. Every curve maps to an explicit PDB entry, official biological assembly and coordinate model.

8f1k__assembly_1__model_1

Assembly 1 · Model 1 · CRYSOL 4.1.3-1-20251215 (887e7ef)

Download this curve (.dat)

8f1k__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

8f1k__assembly_1__model_1 | P(r) · Pending

P(r) will be calculated and displayed separately for the same assembly/model.

Rg（Guinier）	53.27 Å
Rg (electron density)	52.02 Å
Total Rg	52.36 Å
Atom count	30841
Residues	3784
Excluded volume	543510 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`8f1k__assembly_1__model_1`	decameric （10）	Success	4.1.3-1-20251215 (887e7ef)	View Download

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4. Crystallography and Experiment 4. Crystallography & Experiment

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5. Entities and Polymers Entities & Polymers (10)

Entity 1 Entity 1 polymer

Description description	DNA (36-MER)
Molecular weight formula_weight	11104.2 kDa
Source method src_method	syn
Copy count entity_count	2

Polymer Polymer

Polymer type type	polydeoxyribonucleotide
Chain IDs strand_id	A,C
Atom count atom_count	30854

CCAGAAATTGGCACGAAAATTGCAATAAATACAACG

Entity 2 Entity 2 polymer

Description description	DNA-directed RNA polymerase subunit alpha
Molecular weight formula_weight	36558.7 kDa
EC 编号 ec_number	2.7.7.6
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	G,H

MQGSVTEFLKPRLVDIEQVSSTHAKVTLEPLERGFGHTLGNALRRILLSSMPGCAVTEVEIDGVLHEYSTKEGVQEDILEILLNLKGLAVRVQGKDEVILTLNKSGIGPVTAADITHDGDVEIVKPQHVICHLTDENASISMRIKVQRGRGYVPASTRIHSEEDERPIGRLLVDACYSPVERIAYNVEAARVEQRTDLDKLVIEMETNGTIDPEEAIRRAATILAEQLEAFVDLRDVRQPEVKEEKPEFDPILLRPVDDLELTVRSANCLKAEAIHYIGDLVQRTEVELLKTPNLGKKSLTEIKDVLASRGLSLGMRLENWPPASIADE

Source Source

Source organism organism	Escherichia coli
NCBI taxonomy ID ncbi_taxonomy_id	562
Host organism host_organism	Escherichia coli

Entity 3 Entity 3 polymer

Description description	DNA-directed RNA polymerase subunit beta
Molecular weight formula_weight	150820.9 kDa
EC 编号 ec_number	2.7.7.6
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	I

MVYSYTEKKRIRKDFGKRPQVLDVPYLLSIQLDSFQKFIEQDPEGQYGLEAAFRSVFPIQSYSGNSELQYVSYRLGEPVFDVQECQIRGVTYSAPLRVKLRLVIYEREAPEGTVKDIKEQEVYMGEIPLMTDNGTFVINGTERVIVSQLHRSPGVFFDSDKGKTHSSGKVLYNARIIPYRGSWLDFEFDPKDNLFVRIDRRRKLPATIILRALNYTTEQILDLFFEKVIFEIRDNKLQMELVPERLRGETASFDIEANGKVYVEKGRRITARHIRQLEKDDVKLIEVPVEYIAGKVVAKDYIDESTGELICAANMELSLDLLAKLSQSGHKRIETLFTNDLDHGPYISETLRVDPTNDRLSALVEIYRMMRPGEPPTREAAESLFENLFFSEDRYDLSAVGRMKFNRSLLREEIEGSGILSKDDIIDVMKKLIDIRNGKGEVDDIDHLGNRRIRSVGEMAENQFRVGLVRVERAVKERLSLGDLDTLMPQDMINAKPISAAVKEFFGSSQLSQFMDQNNPLSEITHKRRISALGPGGLTRERAGFEVRDVHPTHYGRVCPIETPEGPNIGLINSLSVYAQTNEYGFLETPYRKVTDGVVTDEIHYLSAIEEGNYVIAQANSNLDEEGHFVEDLVTCRSKGESSLFSRDQVDYMDVSTQQVVSVGASLIPFLEHDDANRALMGANMQRQAVPTLRADKPLVGTGMERAVAVDSGVTAVAKRGGVVQYVDASRIVIKVNEDEMYPGEAGIDIYNLTKYTRSNQNTCINQMPCVSLGEPVERGDVLADGPSTDLGELALGQNMRVAFMPWNGYNFEDSILVSERVVQEDRFTTIHIQELACVSRDTKLGPEEITADIPNVGEAALSKLDESGIVYIGAEVTGGDILVGKVTPKGETQLTPEEKLLRAIFGEKASDVKDSSLRVPNGVSGTVIDVQVFTRDGVEKDKRALEIEEMQLKQAKKDLSEELQILEAGLFSRIRAVLVAGGVEAEKLDKLPRDRWLELGLTDEEKQNQLEQLAEQYDELKHEFEKKLEAKRRKITQGDDLAPGVLKIVKVYLAVKRRIQPGDKMAGRHGNKGVISKINPIEDMPYDENGTPVDIVLNPLGVPSRMNIGQILETHLGMAAKGIGDKINAMLKQQQEVAKLREFIQRAYDLGADVRQKVDLSTFSDEEVMRLAENLRKGMPIATPVFDGAKEAEIKELLKLGDLPTSGQIRLYDGRTGEQFERPVTVGYMYMLKLNHLVDDKMHARSTGSYSLVTQQPLGGKAQFGGQRFGEMEVWALEAYGAAYTLQEMLTVKSDDVNGRTKMYKNIVDGNHQMEPGMPESFNVLLKEIRSLGINIELEDE

Source Source

Source organism organism	Escherichia coli
NCBI taxonomy ID ncbi_taxonomy_id	562
Host organism host_organism	Escherichia coli

Entity 4 Entity 4 polymer

Description description	;DNA-directed RNA polymerase subunit beta' ;
Molecular weight formula_weight	158105.7 kDa
EC 编号 ec_number	2.7.7.6
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	J

MKDLLKFLKAQTKTEEFDAIKIALASPDMIRSWSFGEVKKPETINYRTFKPERDGLFCARIFGPVKDYECLCGKYKRLKHRGVICEKCGVEVTQTKVRRERMGHIELASPTAHIWFLKSLPSRIGLLLDMPLRDIERVLYFESYVVIEGGMTNLERQQILTEEQYLDALEEFGDEFDAKMGAEAIQALLKSMDLEQECEQLREELNETNSETKRKKLTKRIKLLEAFVQSGNKPEWMILTVLPVLPPDLRPLVPLDGGRFATSDLNDLYRRVINRNNRLKRLLDLAAPDIIVRNEKRMLQEAVDALLDNGRRGRAITGSNKRPLKSLADMIKGKQGRFRQNLLGKRVDYSGRSVITVGPYLRLHQCGLPKKMALELFKPFIYGKLELRGLATTIKAAKKMVEREEAVVWDILDEVIREHPVLLNRAPTLHRLGIQAFEPVLIEGKAIQLHPLVCAAYNADFDGDQMAVHVPLTLEAQLEARALMMSTNNILSPANGEPIIVPSQDVVLGLYYMTRDCVNAKGEGMVLTGPKEAERLYRSGLASLHARVKVRITEYEKDANGELVAKTSLKDTTVGRAILWMIVPKGLPYSIVNQALGKKAISKMLNTCYRILGLKPTVIFADQIMYTGFAYAARSGASVGIDDMVIPEKKHEIISEAEAEVAEIQEQFQSGLVTAGERYNKVIDIWAAANDRVSKAMMDNLQTETVINRDGQEEKQVSFNSIYMMADSGARGSAAQIRQLAGMRGLMAKPDGSIIETPITANFREGLNVLQYFISTHGARKGLADTALKTANSGYLTRRLVDVAQDLVVTEDDCGTHEGIMMTPVIEGGDVKEPLRDRVLGRVTAEDVLKPGTADILVPRNTLLHEQWCDLLEENSVDAVKVRSVVSCDTDFGVCAHCYGRDLARGHIINKGEAIGVIAAQSIGEPGTQLTMRTFHIGGAASRAAAESSIQVKNKGSIKLSNVKSVVNSSGKLVITSRNTELKLIDEFGRTKESYKVPYGAVLAKGDGEQVAGGETVANWDPHTMPVITEVSGFVRFTDMIDGQTITRQTDELTGLSSLVVLDSAERTAGGKDLRPALKIVDAQGNDVLIPGTDMPAQYFLPGKAIVQLEDGVQISSGDTLARIPQESGGTKDITGGLPRVADLFEARRPKEPAILAEISGIVSFGKETKGKRRLVITPVDGSDPYEEMIPKWRQLNVFEGERVERGDVISDGPEAPHDILRLRGVHAVTRYIVNEVQDVYRLQGVKINDKHIEVIVRQMLRKATIVNAGSSDFLEGEQVEYSRVKIANRELEANGKVGATYSRDLLGITKASLATESFISAASFQETTRVLTEAAVAGKRDELRGLKENVIVGRLIPAGTGYAYHQDRMRRRAAGEAPAAPQVTAEDASASLAELLNAGLGGSDNELELEVLFQGPSSGHHHHHHHHHH

Source Source

Source organism organism	Escherichia coli
NCBI taxonomy ID ncbi_taxonomy_id	562
Host organism host_organism	Escherichia coli

Entity 5 Entity 5 polymer

Description description	DNA-directed RNA polymerase subunit omega
Molecular weight formula_weight	10249.5 kDa
EC 编号 ec_number	2.7.7.6
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	K

MARVTVQDAVEKIGNRFDLVLVAARRARQMQVGGKDPLVPEENDKTTVIALREIEEGLINNQILDVRERQEQQEQEAAELQAVTAIAEGRR

Source Source

Source organism organism	Escherichia coli
NCBI taxonomy ID ncbi_taxonomy_id	562
Host organism host_organism	Escherichia coli

Entity 6 Entity 6 polymer

Description description	RNA polymerase sigma-54 factor
Molecular weight formula_weight	54406.9 kDa
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	M

SEFMKQGLQLRLSQQLAMTPQLQQAIRLLQLSTLELQQELQQALESNPLLEQIDTHEEIDTRETQDSETLDTADALEQKEMPEELPLDASWDTIYTAGTPSGTSGDYIDDELPVYQGETTQTLQDYLMWQVELTPFSDTDRAIATSIVDAVDETGYLTVPLEDILESIGDEEIDIDEVEAVLKRIQRFDPVGVAAKDLRDCLLIQLSQFDKTTPWLEEARLIISDHLDLLANHDFRTLMRVTRLKEDVLKEAVNLIQSLDPRPGQSIQTGEPEYVIPDVLVRKHNGHWTVELNSDSIPRLQINQHYASMCNNARNDGDSQFIRSNLQDAKWLIKSLESRNDTLLRVSRCIVEQQQAFFEQGEEYMKPMVLADIAQAVEMHESTISRVTTQKYLHSPRGIFELKYFFSSHVNTEGGGEASSTAIRALVKKLIAAENPAKPLSDSKLTSLLSEQGIMVARRTVAKYRESLSIPPSNQRKQLV

Source Source

Source organism organism	Escherichia coli
NCBI taxonomy ID ncbi_taxonomy_id	562
Host organism host_organism	Escherichia coli

Entity 7 Entity 7 polymer

Description description	DNA (36-MER)
Molecular weight formula_weight	11045.1 kDa
Source method src_method	syn
Copy count entity_count	2

Polymer Polymer

Polymer type type	polydeoxyribonucleotide
Chain IDs strand_id	B,D

CGTTGTATTTATTGCAATTTTCGTGCCAATTTCTGG

Entity 8 Entity 8 non-polymer

Description description	MAGNESIUM ION
Molecular weight formula_weight	24.3 kDa
Source method src_method	syn
Copy count entity_count	1

Entity 9 Entity 9 non-polymer

Description description	ZINC ION
Molecular weight formula_weight	65.4 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 10 Entity 10 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	10

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6. Fold Classification (SCOP + CATH) 4 domains

CATH v4.4 (4 domains)

Domain ID domain_id	8f1kG01
Class class	2 — Mainly Beta
Architecture architecture	170 — Beta Complex
Topology topology	120 — RNA Polymerase Alpha Subunit; Chain A, domain 2
Homologous superfamily homologous superfamily	12 — DNA-directed RNA polymerase, insert domain

Domain ID domain_id	8f1kH01
Class class	2 — Mainly Beta
Architecture architecture	170 — Beta Complex
Topology topology	120 — RNA Polymerase Alpha Subunit; Chain A, domain 2
Homologous superfamily homologous superfamily	12 — DNA-directed RNA polymerase, insert domain

Domain ID domain_id	8f1kI01
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	150 — RNA polymerase II, Rpb2 subunit, wall domain

Domain ID domain_id	8f1kJ01
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	132 — Topoisomerase I; Chain A, domain 4
Homologous superfamily homologous superfamily	30 — RNA polymerase Rpb1 funnel domain

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Unit-cell length a length_a	1.000 Å
Unit-cell length b length_b	1.000 Å
Unit-cell length c length_c	1.000 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	90.00 °
Unit-cell angle γ angle_gamma	90.00 °
Molecules per unit cell Z z_pdb	—

Space group space_group	P 1
Space-group number int_tables_number	1
Crystal system crystal_system	—

Resolution resolution	2.80 Å
Resolution测定Method resolution_method	—
颗粒数 num_particles	892568

SigN RNA polymerase early-melted intermediate bound to full duplex DNA fragment dhsU36 (-12T)

1. Protein Identity and Related Structures Protein Identity & Related Structures

DNA-directed RNA polymerase subunit alpha

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

DNA-directed RNA polymerase subunit beta

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

;DNA-directed RNA polymerase subunit beta' ;

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

DNA-directed RNA polymerase subunit omega

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

RNA polymerase sigma-54 factor

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

2. Structure Basics 2. Structure Basics

3. Official assembly/model SAXS Official SAXS Profiles

8f1k__assembly_1__model_1

8f1k__assembly_1__model_1 | I(q)

8f1k__assembly_1__model_1 | P(r) · Pending

4. Crystallography and Experiment 4. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

冷冻电镜 EM 3D

5. Entities and Polymers Entities & Polymers (10)

Entity 1 Entity 1 polymer

Polymer Polymer

Entity 2 Entity 2 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 polymer

Polymer Polymer

Source Source

Entity 4 Entity 4 polymer

Polymer Polymer

Source Source

Entity 5 Entity 5 polymer

Polymer Polymer

Source Source

Entity 6 Entity 6 polymer

Polymer Polymer

Source Source

Entity 7 Entity 7 polymer

Polymer Polymer

Entity 8 Entity 8 non-polymer

Entity 9 Entity 9 non-polymer

Entity 10 Entity 10 water

6. Fold Classification (SCOP + CATH) 4 domains

CATH v4.4 (4 domains)

7. Citations (1)