Jun. 4—WATERTOWN — Real estate developer Jake Johnson has purchased the iconic Paddock Arcade and three other downtown buildings.

He also purchased the building that houses the Barton & Loguidice engineering firm, the Key Bank building and the building next to the Paddock Arcade, 1 Public Square.

The $4.55 million deal closed Thursday. He bought the buildings from the owners of 200 Washington St. Associates, managed by Donald G.M. Coon III.

Mr. Coon said he and Mr. Johnson started talking about the deal last October while the two businessmen were attending a city meeting about the city's streetscape project.

"Everything is for sale," he told Mr. Johnson then, adding that they kept talking about selling the properties.

In recent years, Mr. Johnson has acquired numerous properties in and around downtown. He said the new acquisitions are referred in the local real estate world as "trophy properties."

"I always admired them," Mr. Johnson said. "When I had a chance to acquire them, I jumped at it. It just made sense to grow our portfolio."

Starting in a few months, Mr. Johnson will start working on the common areas and exterior of the Paddock. While two units have already been renovated, he intends to complete upgrades on four other market rate apartments.

Some upper floor retail and office space will undergo renovations once he identifies potential tenants. Some prospective tenants already have expressed interest, he said.

He'll use Downtown Revitalization Initiative funding that the previous owners had obtained through the city's $10 million DRI award from 2017.

About $435,000 in DRI funding is still available for the common areas.

Mr. Johnson has already started talking to state economic development officials about transferring the DRI money to his name.

Johnny D's Restaurant, the Paddock Club, Vito's Gourmet and Europe Cakes are among the longtime tenants of the country's oldest still-running indoor mall.

The four properties are assessed at $4,863,400.

The other three properties won't need much in renovations, but he plans to complete some work on their exteriors and common areas. He'll rely on the help of his mother, Patricia, who owns the State Street Market, to lend some creative expertise on sprucing up the Paddock, Mr. Johnson said.

He's become the city's most prolific real estate owner as he has grown his portfolio.

Most recently, he bought the four-story Woodruff Building and its adjoining public garage, 53 Public Square, for $3.7 million.

He owns many of the buildings around Public Square, including the Commerce Building at 26 to 44 Public Square, 16, 18 and 24 Public Square on the south side of the square and 104 Court St. on the north side.

He plans to close on purchasing the Wing Wagon building on Public Square in a few weeks. He also recently purchased a 133-unit apartment building in the Park Avenue neighborhood of Rochester.

Mr. Johnson also confirmed that he sold his share of Maggie's on the River to his partner, Tyler Bartlett.

Mr. Coon said his firm will continue to own a building at 210 Court St. and 230 Franklin St.