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60  structures 4683  species 7  interactions 17642  sequences 74  architectures

Clan: LolA_LolB (CL0048)


LolA/B superfamily Add an annotation

Gram-negative bacteria lipoproteins are anchored to the periplasmic surface of the inner or outer membrane depending on the sorting signal, which is the residue at position 2 of the polypeptide. Five Lol proteins are involved in the sorting and membrane localisation of lipoprotein. An ATP-binding cassette (ABC) transporter, LolCDE, releases outer membrane-specific lipoproteins from the inner membrane, causing the formation of a complex between the released lipoproteins and the periplasmic molecular chaperone LolA. When this complex interacts with outer membrane receptor LolB, the lipoproteins are transferred from LolA to LolB and then localised to the outer membrane. The structures of LolA and LolB are remarkably similar to each other. Both have a hydrophobic cavity consisting of an unclosed beta-barrel and an alpha-helical lid [1,2].

This clan contains 16 families and the total number of domains in the clan is 17642. The clan was built by RD Finn and A Bateman.

Literature references

  1. Takeda K, Miyatake H, Yokota N, Matsuyama S, Tokuda H, Miki K; , EMBO J 2003;22:3199-3209.: Crystal structures of bacterial lipoprotein localization factors, LolA and LolB. PUBMED:12839983 EPMC:12839983
  2. Tokuda H, Matsuyama S; , Biochim Biophys Acta 2004;1693:5-13.: Sorting of lipoproteins to the outer membrane in E. coli. PUBMED:15276320 EPMC:15276320


This clan contains the following 16 member families:

DUF1329 DUF1571 DUF2092 DUF3108 DUF3261 DUF4292 DUF4412 DUF576 LolA LolA_2 LolA_like LolB LppX_LprAFG MucB_RseB Porph_ging VioE

External database links

Domain organisation

Below is a listing of the unique domain organisations or architectures from this clan. More...

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The table below shows the number of occurrences of each domain throughout the sequence database. More...

Pfam family Num. domains Alignment
LolA (PF03548) 4275 (24.2%) View
DUF3108 (PF11306) 2958 (16.8%) View
Porph_ging (PF09697) 1811 (10.3%) View
LolA_like (PF17131) 1572 (8.9%) View
LolB (PF03550) 1469 (8.3%) View
DUF1329 (PF07044) 1278 (7.2%) View
MucB_RseB (PF03888) 1257 (7.1%) View
DUF4292 (PF14125) 865 (4.9%) View
LppX_LprAFG (PF07161) 479 (2.7%) View
DUF2092 (PF09865) 458 (2.6%) View
DUF3261 (PF11659) 341 (1.9%) View
DUF4412 (PF14371) 322 (1.8%) View
LolA_2 (PF16584) 272 (1.5%) View
DUF1571 (PF07608) 217 (1.2%) View
DUF576 (PF04507) 48 (0.3%) View
VioE (PF18234) 20 (0.1%) View
Total: 16 Total: 17642 Clan alignment

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Family relationships

This diagram shows the relationships between members of this clan. More...

Species distribution

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This tree shows the occurrence of the domains in this clan across different species. More...



There are 7 interactions for this clan. More...

Interacting families
DUF1329 DUF1329
DUF576 DUF576
LolA LolA
LolB LolB
MucB_RseB MucB_RseB


For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the MSD group, to allow us to map Pfam domains onto UniProt three-dimensional structures. The table below shows the mapping between the Pfam families in this clan, the corresponding UniProt entries, and the region of the three-dimensional structures that are available for that sequence.

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