Recombinant Phytoplasma mali Acyl carrier protein (acpP)

Definition and Basic Properties

Recombinant Phytoplasma mali acyl carrier protein (acpP) is a 9.8 kDa protein (UniProt ID: B3R0P8) expressed in baculovirus systems for research applications . It is derived from the acpP gene of Candidatus Phytoplasma mali strain AT, a phloem-limited pathogen responsible for apple proliferation disease . The recombinant protein retains the full-length sequence (84 amino acids) and includes a 4'-phosphopantetheine prosthetic group, essential for its role as an acyl group carrier .

Biological Role

In Phytoplasma mali, acpP likely supports:

• Fatty acid biosynthesis: Shuttling malonyl and acetyl groups during elongation .

• Pathogen metabolism: Sustaining bacterial growth in nutrient-limited phloem environments .
  While direct evidence of its role in Phytoplasma mali pathogenicity is limited, homologous ACPs in related bacteria are essential for lipid metabolism and interaction with host plants .

Biosynthesis and Recombinant Production

The recombinant protein is produced via baculovirus-mediated expression in insect cells. Key steps include:

1. Gene Cloning: The acpP gene is inserted into a baculovirus vector.

2. Expression: Insect cells (e.g., Spodoptera frugiperda) are infected with the recombinant virus.

3. Purification: Affinity chromatography isolates the protein with >85% purity .

Current Research Gaps

Despite its availability, studies on Phytoplasma mali acpP are sparse. Existing research focuses on:

• Genetic diversity: Strain-specific variations in Phytoplasma mali genomes, though acpP itself is not highlighted .

• Effector proteins: SAP11CaPm’s role in host manipulation, unrelated to acpP .

Potential Applications

• Antibody development: As an antigen for detecting Phytoplasma mali infections .

• Enzymatic studies: Investigating acyl transfer mechanisms in phytoplasmas .

• Pathogenicity studies: Disrupting acpP to explore its role in bacterial survival .