BISHKEK (Reuters) - Kyrgyz Prime Minister Sadyr Japarov said on Thursday he would step down as acting president of the Central Asian nation in the coming days in order to run in the January 10 presidential election. Parliamentary speaker Talant Mamytov, a close ally of the prime minister, will take over as acting head of state in line with the constitution, Japarov told a news briefing. The former Soviet republic, known for its political volatility, is closely allied with Moscow and hosts a Russian military airbase. Its constitution bars caretaker leaders from running in the presidential elections that they oversee.