Disease relevance of gapA

• CrmA is encoded by the second gene in the gapA operon and shares significant sequence homology to the ORF6 gene of Mycoplasma pneumoniae, which has been shown to play an accessory role in the cytadherence process [1].

High impact information on gapA

• In the third mutant, the insertion was mapped within the crmA gene, which is located immediately downstream of the gapA gene as part of the same operon [2].
• Phenotypic switching in M. gallisepticum hemadsorption (HA) was found to correlate with phase variation of the GapA cytadhesin concurrently with that of the CrmA protein, which exhibits cytadhesin-related features and is encoded by a gene located downstream of the gapA gene as part of the same transcription unit [3].
• In contrast, complementation of R(high) with the entire wild-type gapA operon resulted in the transformant (GCA1) that restored cytadherence to the level found in wild-type R(low) [1].
• Complementation of R(high) with wild-type gapA restored expression in the transformant (GT5) but did not restore the cytadherence phenotype and maintained avirulence in chickens [1].
• GapA and CrmA coexpression is essential for Mycoplasma gallisepticum cytadherence and virulence [1].

Biological context of gapA

• We are currently constructing a shuttle vector containing both the wild-type gapA and crmA for transformation into R high to assess the role of CrmA in the cytadherence process [4].
• Results obtained by sequencing portions of the pvpA, gapA, and mgc2 genes and an uncharacterized surface lipoprotein gene indicated that the field isolates had DNA sequences that ranged from 97.6% to 100%, similar to the 6/85 results [5].

Associations of gapA with chemical compounds

• Sequence analysis confirmed that the insertion of an adenine 105 bp downstream of the gapA translational start codon resulted in premature termination of translation in R high [4].

Other interactions of gapA

• The gene encoding p116 was found to be immediately downstream of gapA in the same operon and was designated crmA [4].
• Four genetic Mycoplasma gallisepticum (MG) polymerase chain reactions (PCRs) (16s rRNA PCR, three newly developed PCR methods that target surface protein genes [mgc2, LP (nested) and gapA (nested)]) were compared for analytical specificity and sensitivity and for diagnostic sensitivity (Se) and specificity of detection from tracheal swabs [6].

Analytical, diagnostic and therapeutic context of gapA

• Digestion of amplicons of gapA-specific PCR with MboI enzyme also produced distinct patterns [7].

References