Mutant/mutation
The mutant lacks expression of BCKDH and expresses GFP throughout the life cycle

Protein (function)
The mitochondrial tricarboxylic acid (TCA) cycle is one of the core metabolic pathways of eukaryotic cells, which contributes to cellular energy generation and provision of essential intermediates for macromolecule synthesis. Apicomplexan parasites possess the complete sets of genes coding for the TCA cycle. However, they lack a key mitochondrial enzyme complex that is normally required for production of acetyl-CoA from pyruvate, allowing further oxidation of glycolytic intermediates in the TCA cycle.
In this paper evidence is presented that  P. bergei utilize a second mitochondrial dehydrogenase complex, BCKDH, that is normally involved in branched amino acid catabolism, to convert pyruvate to acetyl-CoA and further catabolize glucose in the TCA cycle. BCKDH therefore functionally replaces mitochondrial PDH

Genomic and biochemical studies have shown that apicomplexan parasites target their single canonical pyruvate dehydrogenase complex (PDH) to the apicoplast, a non-photosynthetic plastid organelle involved in fatty acid biosynthesis, rather than to the mitochondrion
The absence of a mitochondrial PDH complex in these parasites suggested that glycolytic pyruvate was not converted to acetyl-CoA in the mitochondrion and further catabolised through the TCA cycle
In other organisms, lipids and branched chain amino acids (BCAA) can be catabolised in the mitochondrion to generate acetyl-CoA via pathways not dependent on PDH. However, Plasmodium spp. lack the enzymes needed for the β-oxidation of fatty acids and BCAA degradation. Together, these studies suggested that there was minimal synthesis and catabolism of acetyl-CoA in the mitochondrion. Several studies have recently led to a reappraisal of this model of carbon metabolism in Apicomplexa. These studies suggest that the translocation of the conventional mitochondrial PDH to the apicoplast was associated with a new enzyme activity that functionally replaced PDH in regulating TCA cycle metabolism.
The genomes of the apicomplexan parasites that contain a functional mitochondrion encode all of the subunits of the BCKDH (branched chain ketoacid dehydrogenase) complex, which include the branched chain α-keto acid dehydrogenase E1 subunits
The eukaryotic BCKDH and PDH complexes share many structural and enzymatic properties, catalysing analogous reactions in central carbon metabolism where the initial α-ketoacid is decarboxylated by the E1 subunit - a thiamine diphosphate (TPP)-dependent heterotetramer consisting of two α subunits (E1a) and two β subunits (E1b)
In this paper evidence is provided that BCKDH primarily fulfils the function of mitochondrial PDH in  P. berghei,

Phenotype
Strongly reduced growth of asexual blood stages. Evidence is presented that parasites can only develop into mature schizonts in reticulocytes and not in normocytes, indicating that a functional BCKDH complex is required for the development of P. berghei in mature erythrocytes.
Mutants show also reduced gametocyte production, exflagellation, ookinete and oocyst production. Oocysts show reduced size and absence of sporogony (sporozoite formation).
In this paper evidence is provided that BCKDH primarily fulfils the function of mitochondrial PDH in  P. berghei,

Additional information
Evidence is presented that parasites lacking the BCKDH-E1a subunit exhibit a perturbed TCA cycle.

Other mutants
RMgm-1101: A mutant in which the endogenous bckdh gene is replaced by the P. falciparum bckdh gene