3SXU: E. coli SSB-DNA polymerase III interface

Structure of the E. coli SSB-DNA polymerase III interface. Determined by X-ray diffraction at 1.85 Å resolution. Released 21 Sept 2011.

Method: X-ray diffraction
Resolution: 1.85 Å
Organism: Escherichia coli
Chains: 3
Atoms: 2,349
Mol. weight: 32.86 kDa
Released: 21 Sept 2011

Explore 3SXU in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

3SXU contains 17 α-helices and 15 β-strands across 2 chains. Residue ranges use author residue numbering, as in the PDB file, from PDBe. To see them in 3D, choose the Cartoon representation with Secondary structure coloring: helices, sheets and coils get different colors.

Chain A: 8 helices, 9 β-strands

Element	Residues	Length	Sheet
β-strand	3-8	6	1
α-helix	9	1
β-strand	15	1	2
β-strand	18	1	2
α-helix	20-34	15
β-strand	39-42	4	1
α-helix	46-55	10
β-strand	67-69	3	1
β-strand	80-83	4	1
α-helix	88-90	3
β-strand	95-98	4	1
α-helix	105-109	5
β-strand	112-117	6	1
α-helix	121-123	3
α-helix	124-136	13
α-helix	139	1
β-strand	140-144	5	1

Chain B: 9 helices, 6 β-strands

Element	Residues	Length	Sheet
β-strand	39-42	4	3
α-helix	46-48	3
α-helix	52-61	10
α-helix	65-67	3
β-strand	68-71	4	3
α-helix	73-76	4
α-helix	80	1
β-strand	84	1	4
β-strand	87-90	4	3
α-helix	95-96	2
β-strand	99	1	4
β-strand	102-105	4	3
α-helix	108-113	6
α-helix	115-127	13
α-helix	129-132	4

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
DNA polymerase III subunit chi	A	protein	150	Escherichia coli	P28905 (AlphaFold model)
DNA polymerase III subunit psi	B	protein	138	Escherichia coli	P28632 (AlphaFold model)
SSB peptide	C	protein	5	Escherichia coli	P0AGE0 (AlphaFold model)

Sequence of entity 1 (A), FASTA

>3SXU_1 DNA polymerase III subunit chi (chains A)
GSHMKNATFYLLDNDTTVDGLSAVEQLVCEIAAERWRSGKRVLIACEDEKQAYRLDEALW
ARPAESFVPHNLAGEGPRGGAPVEIAWPQKRSSSRRDILISLRTSFADFATAFTEVVDFV
PYEDSLKQLARERYKAYRVAGFNLNTATWK

Sequence of entity 2 (B), FASTA

>3SXU_2 DNA polymerase III subunit psi (chains B)
MGTSRRDWQLQQLGITQWSLRRPGALQGEIAIAIPAHVRLVMVANDLPALTDPLVSDVLR
ALTVSPDQVLQLTPEKIAMLPQGSHCNSWRLGTDEPLSLEGAQVASPALTDLRANPTARA
ALWQQICTYEHDFFPRND

Sequence of entity 3 (C), FASTA

>3SXU_3 SSB peptide (chains C)
WDIPF

Primary citation

Structure of the SSB-DNA polymerase III interface and its role in DNA replication. Marceau, A.H., Bahng, S., Massoni, S.C. et al. EMBO J (2011) 30:4236-4247. DOI 10.1038/emboj.2011.305 · PubMed

Other PDB entries of the same protein (UniProt P28905 (AlphaFold model), which also has an AlphaFold model), best resolution first:

1EM8 2.1 Å, Crystal structure of chi and psi subunit heterodimer from DNA POL III
9OYH 2.54 Å, Structure of the E. coli clamp loader DnaX-complex loading beta-clamp onto 10-nt gapped…

Browse structure collections

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