Turkish PM Recep Tayyip Erdogan has announced a major cabinet reshuffle after three ministerial resignations over a corruption inquiry.
Mr Erdogan named 10 new ministers - almost half of his total roster - after talks with President Abdullah Gul.
One of those who quit, Environment Minister Erdogan Bayraktar, had urged Mr Erdogan to step down himself.
Police are investigating allegations of illicit money transfers to Iran and bribery for construction projects.
Mr Bayraktar, Economy Minister Zafer Caglayan and Interior Minister Muammer Guler quit after their sons were taken into custody.
All three deny any wrongdoing.
In Istanbul, protesters held a street rally against corruption in the government. There were reports of clashes with riot police late on Wednesday evening.
Commentators believe the scandal stems from a power struggle between Mr Erdogan's government and an influential US-based Muslim cleric, Fethullah Gulen, who is said to have many followers within Turkey's police and judiciary.
Supporters regard the Hizmet movement inspired by Mr Gulen as the benign, modern face of Islam, but critics question its motives.
Mr Gulen, who has denied any involvement in the investigation, left Turkey in 1999 after being accused by the then government of plotting to establish an Islamic state. He was cleared of that charge but has never returned to Turkey and now lives in Pennsylvania.
The government has dismissed dozens of police officials who were either involved in the investigation or thought to be linked to Mr Gulen.
Journalists have been prevented from entering police buildings, leading to claims that the government is trying to impede the investigation.
Mr Erdogan submitted the new cabinet line-up to President Gul late on Wednesday.
Among those who lost his job was EU Affairs Minister Egemen Bagis.
He is accused of being involved in the corruption scandal - but has not been detained or formally charged.
Mr Bayraktar earlier urged the prime minister to resign too.
He insisted that "a great proportion" of construction projects that were under investigation were approved by the prime minister himself, adding: "I want to express my belief that the esteemed prime minister should also resign."
But Mr Erdogan has described the police investigation as a "dirty game". He said it was a plot by foreign and Turkish forces to discredit his government ahead of local elections in March.
But in a further blow to Mr Erdogan, MP and former interior minister Idris Naim Sahin said he was resigning from the ruling AK Party.
'Cash in shoe boxes'
The sons of Mr Caglayan and Mr Guler, along with the chief executive officer of the state-run bank Halkbank, are among 24 people who have been arrested on bribery charges.
Mr Bayraktar's son was detained as part of the inquiry but later released from custody.
Media reports say police seized $4.5m (£2.75m; 3.29m euros) in cash that was stashed in shoe boxes in the home of the bank's CEO, while more than $1m in cash was reportedly discovered in the home of Mr Guler's son, Baris.