Disease relevance of secY

• The Escherichia coli gene secY (pr1A) codes for an integral membrane protein that plays an essential role in protein export [1].
• Isolation of a secY homologue from Bacillus subtilis: evidence for a common protein export pathway in eubacteria [2].
• Nucleotide sequence of the secY gene from Lactococcus lactis and identification of conserved regions by comparison of four SecY proteins [3].
• The protein product of secY has been identified using the gene cloned under the control of the pL promoter of phage lambda in combination with the maxicell system [4].
• The secY gene of BCG has an open reading frame of 441 amino acids with homology to the SecY protein family [5].

High impact information on secY

• It is suggested that the product of the secY gene is a component of the cellular apparatus that is essential for protein secretion across the cytoplasmic membrane [6].
• The secY gene is distinct from those genes previously known to specify ribosomal proteins, yet it is within the spc operon [6].
• The mutant phenotype is complemented by a plasmid carrying only the secY gene under lac promoter control [7].
• In contrast, the decreased level of expression of the secY gene leads to defective protein secretion and defective cell growth [7].
• The mutant has a single base change in the middle of the secY gene, which would result in the replacement of a glycine residue by aspartic acid in the protein product [8].

Biological context of secY

• These results demonstrate that the gene secY (prlA) is essential for protein translocation across the E. coli cytoplasmic membrane [8].
• Its translocation across the plasma membrane requires the membrane potential and the secY gene product [9].
• The secY promoter region (psecY) contained two activities, each principally functioning in the stationary growth phase when high protein export is required [10].
• A cold-sensitive secY mutant (secY125) with an amino acid substitution in the first periplasmic domain causes in vivo retardation of protein export [11].
• Its NH2-terminal sequence confirmed the secY reading frame and the translation initiation site assigned previously [12].

Anatomical context of secY

• The mutant cells complemented by secY can grow and synthesize proteins at normal rates and abundances at 42 degrees C, despite the fact that their ribosomes contain barely detectable levels of L15 [7].
• B. subtilis secY coded for a hypothetical product 41% identical to E. coli SecY, a protein thought to contain 10 membrane-spanning segments and 11 hydrophilic regions, six of which are exposed to the cytoplasm and five to the periplasm [2].

Other interactions of secY

• It has been suggested that the stability of SecY mRNA depends on rpmJ unless a rho-independent terminator is inserted immediately downstream of secY [13].

References