2-O-(beta-D-mannosyl)-bis(myo-inositol) 1,3'-phosphate + GDP-alpha-D-mannose <=> 2-O-(beta-D-mannosyl-(1->2)-beta-D-mannosyl)-bis(myo-inositol) 1,3'-phosphate + GDP + H(+)
2-o-(beta-d-mannosyl)-bis(myo-inositol) 1,3'-phosphate + gdp-alpha-d-mannose <=> 2-o-(beta-d-mannosyl-(1->2)-beta-d-mannosyl)-bis(myo-inositol) 1,3'-phosphate + gdp + h(+)
2-O-(beta-D-mannosyl)-bis(myo-inositol) 1,3'-phosphate + GDP-alpha-D-mannose <=> 2-O-(beta-D-mannosyl-(1->2)-beta-D-mannosyl)-bis(myo-inositol) 1,3'-phosphate + GDP + H(+)
2-o-(beta-d-mannosyl)-bis(myo-inositol) 1,3'-phosphate + gdp-alpha-d-mannose <=> 2-o-(beta-d-mannosyl-(1->2)-beta-d-mannosyl)-bis(myo-inositol) 1,3'-phosphate + gdp + h(+)