Disease relevance of OXA1L

• beta-lactamases in Shigella flexneri isolates from Hong Kong and Shanghai and a novel OXA-1-like beta-lactamase, OXA-30 [1].
• Aggregation of human platelets by Streptococcus gordonii DL1, an interaction implicated in the pathogenesis of infective endocarditis, requires the expression of hsa, the gene encoding the sialic acid-binding adhesin (Hsa) of this organism [2].
• Correlation between in vitro susceptibility results for amoxicillin-clavulanate (AMC) and ampicillin-sulbactam (SAM) was studied using 136 clinical and control strains of Enterobacteriaceae harboring TEM-1, SHV-1 or OXA-1-like beta-lactamases [3].

High impact information on OXA1L

• GspB and Hsa are homologous serine-rich surface glycoproteins of Streptococcus gordonii strains M99 and Challis, respectively, that mediate the binding of these organisms to platelet membrane glycoprotein (GP) Ibalpha [4].
• To further assess the mechanisms for GspB and Hsa binding, we investigated the binding of the BRs of GspB and Hsa (expressed as glutathione S-tranferase fusion proteins) to sialylated glycoproteins in vitro [4].
• Both GspB and Hsa consist of an N-terminal putative signal peptide, a short serine-rich region, a region (BR) that is rich in basic amino acids, a longer serine-rich region and a C-terminal cell wall anchoring domain [4].
• GspB and Hsa are homologous surface glycoproteins of Streptococcus gordonii that bind sialic acid moieties on platelet membrane glycoprotein Ibalpha [5].
• The results suggest that Hsa directs primary adhesion events for S. gordonii DL1 (Challis) with immobilized gp340, epithelial cells, and platelets [6].

Biological context of OXA1L

• The OXA1L gene that controls cytochrome oxidase assembly maps to the 14q11.2 region of the human genome [7].
• Based on the results of yeast knockouts of these four proteins, we have sequenced the open reading frame of OXA1L in eight patients with an enzymatic deficiency of complexes I and IV [8].
• The screening of OXA1L mutation in patients with multiple respiratory chain deficiency is now feasible [9].
• The OXA1L gene (5 kb) is composed of 10 exons and 9 introns and contains a 24 N-terminal amino-acid stretch is characteristic of a mitochondrial presequence [9].
• Further analysis of mutant phenotypes showed that the Hsa and AgI/II proteins mediated adhesion of S. gordonii DL1 to human HEp-2 epithelial cells [6].

Associations of OXA1L with chemical compounds

• Adherence of S. gordonii DL1 (Challis) to surface-bound gp340 was dependent upon expression of the sialic acid binding adhesin Hsa [10].
• The gene encoding the OXA-1-like enzyme from one isolate (CH-07) was cloned, sequenced, and found to differ from bla(OXA-1) at codon 131 (AGA-->GGA; Arg to Gly), resulting in the novel designation OXA-30 [1].

Other interactions of OXA1L

• TEM-1-like and OXA-1-like enzymes were identified in 21 and 79% of the strains, respectively, by isoelectric focusing (IEF) [1].

Analytical, diagnostic and therapeutic context of OXA1L

• Using the long PCR amplification procedure, we have characterized the organization and complete sequence of OXA1L, a gene involved in the assembly of several complexes of the mitochondrial respiratory chain [9].
• As measured by surface plasmon resonance kinetic analysis, GspB- and Hsa-derived fusion proteins had high affinity for GPIbalpha, but with somewhat different dissociation constants [4].
• Moreover, far Western blotting using platelet membrane proteins revealed that GPIbalpha is the principal receptor for GspB and Hsa on human platelets [4].

References