5d6v | pdb_00005d6v
PduJ K25A mutant, from Salmonella enterica serovar Typhimurium LT2, PduJ mutant
Structural highlights
FunctionPDUJ_SALTY One of the major shell proteins of the bacterial microcompartment (BMC) dedicated to 1,2-propanediol (1,2-PD) degradation. The isolated BMC shell component protein ratio for J:A:B':B:K:T:U is approximately 15:10:7:6:1:1:2 (PubMed:12923081). At least one of PduA or PduJ is required for BMC assembly; it must be encoded as the first gene in the pdu operon (PubMed:33227310, PubMed:27561553). Required for structural integrity of BMCs and to mitigate propionaldehyde toxicity, probably joins facets responsible for BMC closure (PubMed:21239588). Edge residues (particularly Lys-25) are important for function and assembly of the BMC (PubMed:24747050). 80% identical to PduA; although their pore regions appear structurally identical, unlike PduA plays no role in 1,2-PD diffusion into or out of the BMC shell. If pduJ is cloned in the chromosomal position of pduA it is able to complement a pduA deletion; it then has a functional pore as it assumes the transport functions of PduA (PubMed:27561553). Overexpression of this protein leads to aberrant filaments that extend the length of the cell, cross the cleavage furrow and impair division. The filaments form nanotubes with a hollow center (PubMed:33227310). Modeling suggests PduJ is probably the hub for binding multiple enzymes to the interior of the BMC; modeling suggests PduC, PduD, PduG and PduM are targeted to PduJ (Probable).[1] [2] [3] [4] [5] [6] The 1,2-propanediol (1,2-PD) degradation bacterial microcompartment (BMC) concentrates low levels of 1,2-PD catabolic enzymes, concentrates volatile reaction intermediates thus enhancing pathway flux and keeps the level of toxic, mutagenic propionaldehyde low.[7] [8] Publication Abstract from PubMedBacterial microcompartments (MCPs) are complex organelles that consist of metabolic enzymes encapsulated within a protein shell. In this study, we investigate the function of the PduJ MCP shell protein. PduJ is 80% identical in amino acid sequence to PduA and both are major shell proteins of the 1,2-propanediol (1,2-PD) utilization (Pdu) MCP of Salmonella. Prior studies showed that PduA mediates the transport of 1,2-PD (the substrate) into the Pdu MCP. Surprisingly, however, results presented here establish that PduJ has no role 1,2-PD transport. The crystal structure revealed that PduJ was nearly identical to that of PduA and, hence, offered no explanation for their differential functions. Interestingly, however, when a pduJ gene was placed at the pduA chromosomal locus, the PduJ protein acquired a new function, the ability to mediate 1,2-PD transport into the Pdu MCP. To our knowledge, these are the first studies to show that that gene location can determine the function of a MCP shell protein. We propose that gene location dictates protein-protein interactions essential to the function of the MCP shell. The function of the PduJ microcompartment shell protein is determined by the genomic position of its encoding gene.,Chowdhury C, Chun S, Sawaya MR, Yeates TO, Bobik TA Mol Microbiol. 2016 Sep;101(5):770-83. doi: 10.1111/mmi.13423. Epub 2016 Jun 7. PMID:27561553[9] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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